The role and relevance of phospholipase D1 during growth and dimorphism of Candida albicans.

PubMed

Hube, B; Hess, D; Baker, C A; Schaller, M; Schäfer, W; Dolan, J W

2001-04-01

The phosphatidylcholine-specific phospholipase D1 (PLD1) in Saccharomyces cerevisiae is involved in vesicle transport and is essential for sporulation. The gene encoding the homologous phospholipase D1 from Candida albicans (PLD1) was used to study the role of PLD1 in this pathogenic fungus. In vitro and in vivo expression studies using Northern blots and reverse transcriptase-PCR showed low PLD1 mRNA levels in defined media supporting yeast growth and during experimental infection, while enhanced levels of PLD1 transcripts were detected during the yeast to hyphal transition. To study the relevance of PLD1 during yeast and hyphal growth, an essential part of the gene was deleted in both alleles of two isogenic strains. In vitro PLD1 activity assays showed that pld1 mutants produced no detectable levels of phosphatidic acid, the hydrolytic product of PLD1 activity, and strongly reduced levels of diacylglycerol, the product of lipid phosphate phosphohydrolase, suggesting no or a negligible background PLD1 activity in the pld1 mutants. The pld1 mutants showed no growth differences compared to the parental wild-type in liquid complex and minimal media, independent of the growth temperature. In addition, growth rates of pld1 mutants in media with protein as the sole source of nitrogen were similar to growth rates of the wild-type, indicating that secretion of proteinases was not reduced. Chlamydospore formation was normal in pld1 mutants. When germ tube formation was induced in liquid media, pld1 mutants showed similar rates of yeast to hyphal transition compared to the wild-type. However, no hyphae formation was observed on solid Spider medium, and cell growth on cornmeal/Tween 80 medium indicated aberrant morphogenesis. In addition, pld1 mutants growing on solid media had an attenuated ability to invade the agar. In a model of oral candidosis, pld1 mutants showed no attenuation of virulence. In contrast, the mutant was less virulent in two different mouse models. These data suggest that PLD1 is not essential for growth and oral infections. However, they also suggest that a prominent part of the phosphatidic acid and diacylglycerol pools is produced by PLD1 and that the level of these components is important for morphological transitions under certain conditions in C. albicans.

Public acceptance of management methods under different human-wildlife conflict scenarios.

PubMed

Liordos, Vasilios; Kontsiotis, Vasileios J; Georgari, Marina; Baltzi, Kerasia; Baltzi, Ioanna

2017-02-01

Wildlife management seeks to minimise public controversy for successful application of wildlife control methods. Human dimensions research in wildlife seeks a better understanding of public preferences for effective human-wildlife conflict resolution. In face to face interviews, 630 adults in Greece were asked to rate on a 5-point Likert-like scale their acceptance of 3 management methods, i.e., do nothing, non-lethal control, and lethal control, in the context of 5 human-wildlife conflict scenarios: 1) corvids damage crops; 2) starlings damage crops; 3) starlings foul urban structures; 4) coypus damage crops; and 5) coypus transfer disease. Univariate GLMs determined occupation, hunting membership and their interaction as the stronger predictors of public acceptance, generating 4 stakeholder groups: the general public, farmers, hunters, and farmers-hunters. Differences in acceptance and consensus among stakeholder groups were assessed using the Potential for Conflict Index 2 (PCI 2 ). All 4 stakeholder groups agreed that doing nothing was unacceptable and non-lethal control acceptable in all 5 scenarios, with generally high consensus within and between groups. The lethal control method was more controversial and became increasingly more acceptable as the severity of scenarios was increased and between non-native and native species. Lethal control was unacceptable for the general public in all scenarios. Farmers accepted lethal methods in the corvids and starlings scenarios, were neutral in the coypus damage crops scenario, whereas they accepted lethal control when coypus transfer disease. Hunters' opinion was neutral in the corvids, starlings and coypus damage crops and starlings foul urban structures scenarios, but they accepted lethal methods in the coypus transfer disease scenario. Farmers-hunters considered lethal control acceptable in all 5 scenarios. Implications from this study could be used for designing a socio-ecological approach which incorporates wildlife management with public interests. The studied species have a wide distribution, therefore present findings might also prove useful elsewhere. Copyright © 2016 Elsevier B.V. All rights reserved.

Chronic Glaucoma in Dogs: Relationships Between Histologic Lesions and the Gonioscopic Diagnosis of Pectinate Ligament Dysplasia.

PubMed

Bauer, B S; Sandmeyer, L S; Philibert, H; Feng, C X; Grahn, B H

2016-11-01

Pectinate ligament dysplasia (PLD) is a common cause of canine glaucoma and the definitive clinical diagnosis is based on gonioscopy. Although the histologic lesions of PLD have been described, it has not been determined whether these changes are specific for PLD or if similar histologic changes can develop as a consequence of secondary glaucoma. The filtration angles of 61 enucleated canine globes with chronic glaucoma were evaluated with light microscopy by 3 examiners who were masked to the clinical history, signalment, and gonioscopic results. A histologic diagnosis of PLD versus non-PLD was determined by each examiner based on previously reported morphologic criteria and compared with the clinical gonioscopic diagnosis. Of the 61 enucleated glaucomatous eyes, 40 were clinically diagnosed with PLD. For all 3 examiners, a histologic diagnosis of PLD corresponded poorly with the clinical diagnosis of PLD (range of kappa score: 0.149-0.269; range of AUC: 0.592-0.621). There was no difference between examiners in their ability to correctly diagnose PLD histologically (P = .978). A fair degree of agreement was noted among examiners in obtaining their suspected histologic diagnosis of PLD (kappa score 0.256). No individual or sets of histologic ICA features were consistent with clinical PLD. The results indicate the histologic ICA changes proposed to be characteristic of PLD are also noted in canine globes affected with chronic secondary glaucoma. Therefore, using routine histologic evaluation, a histologic diagnosis of PLD is not possible in the face of chronic canine glaucoma. © The Author(s) 2016.

Pelagic larval duration predicts extinction risk in a freshwater fish clade.

PubMed

Douglas, Morgan; Keck, Benjamin P; Ruble, Crystal; Petty, Melissa; Shute, J R; Rakes, Patrick; Hulsey, C Darrin

2013-01-01

Pelagic larval duration (PLD) can influence evolutionary processes ranging from dispersal to extinction in aquatic organisms. Using estimates of PLD obtained from species of North American darters (Percidae: Etheostomatinae), we demonstrate that this freshwater fish clade exhibits surprising variation in PLD. Comparative analyses provide some evidence that higher stream gradients favour the evolution of shorter PLD. Additionally, similar to patterns in the marine fossil record in which lower PLD is associated with greater extinction probability, we found a reduced PLD in darter lineages was evolutionarily associated with extinction risk. Understanding the causes and consequences of PLD length could lead to better management and conservation of organisms in our increasingly imperiled aquatic environments.

Phospholipase D Is Involved in the Formation of Golgi Associated Clathrin Coated Vesicles in Human Parotid Duct Cells

PubMed Central

Brito de Souza, Lorena; Pinto da Silva, Luis Lamberti; Jamur, Maria Célia; Oliver, Constance

2014-01-01

Phospholipase D (PLD) has been implicated in many cellular functions, such as vesicle trafficking, exocytosis, differentiation, and proliferation. The aim of this study was to characterize the role of PLD in HSY cells, a human cell line originating from the intercalated duct of the parotid gland. As the function and intracellular localization of PLD varies according to cell type, initially, the intracellular localization of PLD1 and PLD2 was determined. By immunofluorescence, PLD1 and PLD2 both showed a punctate cytoplasmic distribution with extensive co-localization with TGN-46. PLD1 was also found in the nucleus, while PLD2 was associated with the plasma membrane. Treatment of cells with the primary alcohol 1-butanol inhibits the hydrolysis of phosphatidylcoline by PLD thereby suppressing phosphatidic acid (PA) production. In untreated HSY cells, there was only a slight co-localization of PLD with the clathrin coated vesicles. When HSY cells were incubated with 1-butanol the total number of clathrin coated vesicles increased, especially in the juxtanuclear region and the co-localization of PLD with the clathrin coated vesicles was augmented. Transmission electron microscopy confirmed that the number of Golgi-associated coated vesicles was greater. Treatment with 1-butanol also affected the Golgi apparatus, increasing the volume of the Golgi saccules. The decrease in PA levels after treatment with 1-butanol likewise resulted in an accumulation of enlarged lysosomes in the perinuclear region. Therefore, in HSY cells PLD appears to be involved in the formation of Golgi associated clathrin coated vesicles as well as in the structural maintenance of the Golgi apparatus. PMID:24618697

Fear Potentiated Startle Increases Phospholipase D (PLD) Expression/Activity and PLD-Linked Metabotropic Glutamate Receptor Mediated Post-Tetanic Potentiation in Rat Amygdala

PubMed Central

Krishnan, Balaji; Scott, Michael T.; Pollandt, Sebastian; Schroeder, Bradley; Kurosky, Alexander; Shinnick-Gallagher, Patricia

2016-01-01

Long-term memory (LTM) of fear stores activity dependent modifications that include changes in amygdala signaling. Previously, we identified an enhanced probability of release of glutamate mediated signaling to be important in rat fear potentiated startle (FPS), a well-established translational behavioral measure of fear. Here, we investigated short- and long-term synaptic plasticity in FPS involving metabotropic glutamate receptors (mGluRs) and associated downstream proteomic changes in the thalamic-lateral amygdala pathway (Th-LA). Aldolase A, an inhibitor of phospholipase D (PLD), expression was reduced, concurrent with significantly elevated PLD protein expression. Blocking the PLD-mGluR signaling significantly reduced PLD activity. While transmitter release probability increased in FPS, PLD-mGluR agonist and antagonist actions were occluded. In the unpaired group (UNP), blocking the PLD-mGluR increased while activating the receptor decreased transmitter release probability, consistent with decreased synaptic potentials during tetanic stimulation. FPS Post-tetanic potentiation (PTP) immediately following long-term potentiation (LTP) induction was significantly increased. Blocking PLD-mGluR signaling prevented PTP and reduced cumulative PTP probability but not LTP maintenance in both groups. These effects are similar to those mediated through mGluR7, which is co-immunoprecipitated with PLD in FPS. Lastly, blocking mGluR-PLD in the rat amygdala was sufficient to prevent behavioral expression of fear memory. Thus, our study in the Th-LA pathway provides the first evidence for PLD as an important target of mGluR signaling in amygdala fear-associated memory. Importantly, the PLD-mGluR provides a novel therapeutic target for treating maladaptive fear memories in posttraumatic stress and anxiety disorders. PMID:26748024

Pectinate ligament dysplasia in the Border Collie, Hungarian Vizsla and Golden Retriever.

PubMed

Oliver, James A C; Ekiri, Abel B; Mellersh, Cathryn S

2017-03-18

Pectinate ligament dysplasia (PLD) is significantly associated with primary closed angle glaucoma (PCAG) in several dog breeds. Gonioscopy screening for PLD is advised in breeds in which PLD and PCAG are particularly prevalent in order that affected dogs may be eliminated from the breeding population. The Border Collie (BC), Hungarian Vizsla (HV) and Golden Retriever (GR) breeds are currently under investigation for PLD by the British Veterinary Association/Kennel Club/International Sheep Dog Society (BVA/KC/ISDS) Eye Scheme. The authors aimed to determine the prevalence of PLD in UK populations of BC, HV and GR and to investigate possible associations between the degree of PLD and age and sex. Gonioscopy was performed in 102 BCs, 112 HVs and 230 GRs and the percentage of iridocorneal angle affected by PLD was estimated and classified as unaffected (0 per cent), mildly affected (<20 per cent), moderately affected (20-90 per cent) or severely affected (>90 per cent). Eleven of 102 (13.8 per cent) BCs, 16/112 (14.3 per cent) HVs and 60/230 (26.1 per cent) GRs were moderately or severely affected by PLD. The prevalence of PLD was significantly higher in GR than both BC and HV. There was a significant positive correlation between PLD and age in the HV and GR but not in the BC. There was no association between PLD and sex in any breed. British Veterinary Association.

Identification of Drugs Inducing Phospholipidosis by Novel in vitro Data

PubMed Central

Muehlbacher, Markus; Tripal, Philipp; Roas, Florian; Kornhuber, Johannes

2012-01-01

Drug-induced phospholipidosis (PLD) is a lysosomal storage disorder characterized by the accumulation of phospholipids within the lysosome. This adverse drug effect can occur in various tissues and is suspected to impact cellular viability. Therefore, it is important to test chemical compounds for their potential to induce PLD during the drug design process. PLD has been reported to be a side effect of many commonly used drugs, especially those with cationic amphiphilic properties. To predict drug-induced PLD in silico, we established a high-throughput cell-culture-based method to quantitatively determine the induction of PLD by chemical compounds. Using this assay, we tested 297 drug-like compounds at two different concentrations (2.5 μm and 5.0 μm). We were able to identify 28 previously unknown PLD-inducing agents. Furthermore, our experimental results enabled the development of a binary classification model to predict PLD-inducing agents based on their molecular properties. This random forest prediction system yields a bootstrapped validated accuracy of 86 %. PLD-inducing agents overlap with those that target similar biological processes; a high degree of concordance with PLD-inducing agents was identified for cationic amphiphilic compounds, small molecules that inhibit acid sphingomyelinase, compounds that cross the blood–brain barrier, and compounds that violate Lipinski’s rule of five. Furthermore, we were able to show that PLD-inducing compounds applied in combination additively induce PLD. PMID:22945602

Quercetin-induced downregulation of phospholipase D1 inhibits proliferation and invasion in U87 glioma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Mi Hee; Min, Do Sik, E-mail: minds@pusan.ac.kr

Highlights: {yields} Quercetin, a bioactive flavonoid, suppresses expression and enzymatic activity of phospholipase D1. {yields} Quercetin abolishes NFkB-induced phospholipase D1 expression via inhibition of NFkB transactivation. {yields} Quercetin-induced suppression of phospholipase D1 inhibits invasion and proliferation of human glioma cells. -- Abstract: Phospholipase D (PLD) has been recognized as a regulator of cell proliferation and tumorigenesis, but little is known about the molecules regulating PLD expression. Thus, the identification of small molecules inhibiting PLD expression would be an important advance in PLD-mediated physiology. Quercetin, a ubiquitous bioactive flavonoid, is known to inhibit proliferation and induce apoptosis in a variety ofmore » cancer cells. In the present study, we examined the effect of quercetin on the expression of PLD in U87 glioma cells. Quercetin significantly suppressed the expression of PLD1 at the transcriptional level. Moreover, quercetin abolished the protein expression of PLD1 in a time and dose-dependent manner, as well as inhibited PLD activity. Quercetin suppressed NF{kappa}B-induced PLD1 expression via inhibition of NFkB transactivation. Furthermore, quercetin inhibited activation and invasion of metalloproteinase-2 (MMP-2), a key modulator of glioma cell invasion, induced by phosphatidic acid (PA), a product of PLD activity. Taken together these data demonstrate that quercetin abolishes PLD1 expression and subsequently inhibits invasion and proliferation of glioma cells.« less

Selective induction of phospholipase D1 in pathogen-activated human monocytes.

PubMed

Locati, M; Riboldi, E; Bonecchi, R; Transidico, P; Bernasconi, S; Haribabu, B; Morris, A J; Mantovani, A; Sozzani, S

2001-08-15

Phospholipase D (PLD) activation is part of the complex signalling cascade induced during phagocyte activation. Two PLD isoforms have been cloned, but their role in phagocyte functions is still poorly defined. We report that resting fresh circulating human monocytes expressed PLD1. PLD1 protein expression was rapidly down-regulated during cell culture. Lipopolysaccharide and pathogen-derived agonists (Candida albicans, arabinoside-terminated lipoarabinomannan and Gram-positive bacteria, but not mannose-capped lipoarabinomannan or double-stranded RNA) strongly induced PLD1 expression at both the mRNA and protein levels. Pro-inflammatory cytokines [interleukin (IL)-1beta and tumour necrosis factor alpha] had only a weak effect, whereas immune cytokines (IL-6 and interferon gamma), anti-inflammatory cytokines (IL-13 and IL-10) and chemoattractants (fMet-Leu-Phe and macrophage chemoattractant protein 1) were inactive. None of the agonists tested induced significant changes in the basal expression of PLD2 mRNA. Consistent with PLD1 up-regulation was the observation that PLD enzymic activity was higher in monocytes treated with active-pathogen-derived agonists than in control cells, when stimulated with PMA or with chemotactic agonists (fMet-Leu-Phe and C5a). Thus PLD2 seems to be a constitutive enzyme in circulating monocytes. Conversely, PLD1 is an inducible protein, rapidly regulated during culture conditions and selectively induced during cell activation. Therefore PLD1 might have a relevant role in immune responses against pathogens and in chronic inflammation.

Rebamipide-induced downregulation of phospholipase D inhibits inflammation and proliferation in gastric cancer cells

PubMed Central

Kang, Dong Woo; Min, Gyesik; Park, Do Yoon; Hong, Ki Whan

2010-01-01

Rebamipide a gastroprotective drug, is clinically used for the treatment of gastric ulcers and gastritis, but its actions on gastric cancer are not clearly understood. Phospholipase D (PLD) is overexpressed in various types of cancer tissues and has been implicated as a critical factor in inflammation and carcinogenesis. However, whether rebamipide is involved in the regulation of PLD in gastric cancer cells is not known. In this study, we showed that rebamipide significantly suppressed the expression of both PLD1 and PLD2 at a transcriptional level in AGS and MKN-1 gastric cancer cells. Downregulation of PLD expression by rebamipide inhibited its enzymatic activity. In addition, rebamipide inhibited the transactivation of nuclear factor kappa B (NFκB), which increased PLD1 expression. Rebamipide or PLD knockdown significantly suppressed the expression of genes involved in inflammation and proliferation and inhibited the proliferation of gastric cancer cells. In conclusion, rebamipide-induced downregulation of PLD may contribute to the inhibition of inflammation and proliferation in gastric cancer. PMID:20625243

Requirements and effects of palmitoylation of rat PLD1.

PubMed

Xie, Z; Ho, W T; Exton, J H

2001-03-23

Rat brain phospholipase D1 (rPLD1) has two highly conserved motifs (HXKX(4)D), denoted HKD, located in the N- and C-terminal halves, which are required for phospholipase D activity. The two halves of rPLD1 can associate in vivo, and the association is essential for catalytic activity and Ser/Thr phosphorylation of the enzyme. In this study, we found that this association is also required for palmitoylation of rPLD1, which occurs on cysteines 240 and 241. In addition, palmitoylation of rPLD1 requires the N-terminal sequence but not the conserved C-terminal sequence, since rPLD1 that lacks the first 168 amino acids is not palmitoylated in vivo, while the inactive C-terminal deletion mutant is. Palmitoylation of rPLD1 is not necessary for catalytic activity, since N-terminal truncation mutants lacking the first 168 or 319 amino acids exhibit high basal activity although they cannot be stimulated by protein kinase C (PKC). The lack of response to PKC is not due to the lack of palmitoylation, since mutation of both Cys(240) and Cys(241) to alanine in full-length rPLD1 abolishes palmitoylation, but the mutant still retains basal activity and responds to PKC. Palmitoylation-deficient rPLD1 can associate with crude membranes; however, the association is weakened. Wild type rPLD1 remains membrane-associated when extracted with 1 m NaCl or Na(2)CO(3) (pH 11), while rPLD1 mutants that lack palmitoylation are partially released. In addition, we found that palmitoylation-deficient mutants are much less modified by Ser/Thr phosphorylation compared with wild type rPLD1. Characterization of the other cysteine mutations of rPLD1 showed that mutation of cysteine 310 or 612 to alanine increased basal phospholipase D activity 2- and 4-fold, respectively. In summary, palmitoylation of rPLD1 requires interdomain association and the presence of the N-terminal 168 amino acids. Mutations of cysteines 240 and 241 to alanine abolish the extensive Ser/Thr phosphorylation of the enzyme and weaken its association with membranes.

Direct comparison of two pegylated liposomal doxorubicin formulations: is AUC predictive for toxicity and efficacy?

PubMed

Cui, Jingxia; Li, Chunlei; Guo, Wenmin; Li, Yanhui; Wang, Caixia; Zhang, Li; Zhang, Lan; Hao, Yanli; Wang, Yongli

2007-04-02

Rationally designed liposomes could improve the therapeutic indexes of chemotherapeutic drugs, which is due to alterations in the pharmacokinetics and biodistribution of encapsulated drugs. For traditional drug delivery systems, the accumulation of drugs in healthy and malignant tissues could be correlated with toxicity and efficacy. Some previous studies also indicate that the higher tumor AUC, the better therapeutic efficacy, suggestive of the possible existence of positive correlation. Are AUC values of liposomal drugs really predictive? For the purpose to address this question, we designed two pegylated liposomal doxorubicin formulations (PLD-75 and PLD-100), which had the same lipid/drug ratio and bilayer composition, but different size and internal ammonium sulfate concentration. In vitro drug retention experiments revealed that drug was released at a faster rate from PLD-75, a small size formulation. The plasma pharmacokinetics of PLD-75 was similar to that of PLD-100, regardless of whether the mice were tumor-free or not. It should be noted, though, that in tumor-bearing mice the plasma doxorubicin level in PLD-75 group was only about 59% of that in PLD-100 group at 48 h post injection. Furthermore, their biodistribution behavior in S-180 tumor-bearing KM mice was significantly different. Compared with animals receiving PLD-100, those receiving PLD-75 showed a 19.2%, 27.8%, and 23.5% decrease in liver (p<0.01), spleen (p<0.001) and lung (p<0.05) AUC, respectively. In other healthy tissues except kidney, the drug deposition also reduced by 10-15%, but the difference was not significant. The tumor AUC after administration of PLD-100 and PLD-75 were 1285.3 ugh/g and 762.0 ugh/g, respectively (p<0.001). Maximum drug levels achieved in the tumors were 33.80 microg/g (for PLD-100) and 20.85 microg/g (for PLD-75), and peak tumor concentration was achieved faster in PLD-75 group. However, enhanced drug accumulation does not mean increased antineoplastic effect, and at the same doxorubicin dose level, PLD-75 was more efficacious. As for toxicity studies, PLD-75 caused more rapid and severe body weight loss despite the fact that drug accumulation in healthy tissues was reduced. Our data indicate that liposomal systems are more complicated than conventional drug delivery systems, and it is hard to predict the toxicity and efficacy of liposomal drugs through the measure of liposomal drug accumulation.

Development of Alendronate-conjugated Poly (lactic-co-glycolic acid)-Dextran Nanoparticles for Active Targeting of Cisplatin in Osteosarcoma

PubMed Central

Liu, Ping; Sun, Liang; Zhou, Dong-sheng; Zhang, Peng; Wang, Yong-hui; Li, Dong; Li, Qing-hu; Feng, Rong-jie

2015-01-01

In this study, we developed a novel poly (lactic-co-glycolic acid)-dextran (PLD)-based nanodelivery system to enhance the anticancer potential of cisplatin (CDDP) in osteosarcoma cells. A nanosized CDDP-loaded PLGA-DX nanoparticle (PLD/CDDP) controlled the release rate of CDDP up to 48 h. In vitro cytotoxicity assay showed a superior anticancer effect for PLD/CDDP and with an appreciable cellular uptake via endocytosis-mediated pathways. PLD/CDDP exhibited significant apoptosis of MG63 cancer cells compared to that of free CDDP. Approximately ~25% of cells were in early apoptosis phase after PLD/CDDP treatment comparing to ~15% for free CDDP after 48h incubation. Similarly, PLD/CDDP exhibited ~30% of late apoptosis cells comparing to only ~8% for free drug treatment. PLD/CDDP exhibited significantly higher G2/M phase arrest in MG63 cells than compared to free CDDP with a nearly 2-fold higher arrest in case of PLD/CDDP treated group (~60%). Importantly, PLD/CDDP exhibited a most significant anti-tumor activity with maximum tumor growth inhibition. The superior inhibitory effect was further confirmed by a marked reduction in the number of CD31 stained tumor blood vessels and decrease in the Ki67 staining intensity for PLD/CDDP treated animal group. Overall, CDDP formulations could provide a promising and most effective platform in the treatment of osteosarcoma. PMID:26619950

Disruption of the Phospholipase D Gene Attenuates the Virulence of Aspergillus fumigatus

PubMed Central

Li, Xianping; Gao, Meihua; Han, Xuelin; Tao, Sha; Zheng, Dongyu; Cheng, Ying; Yu, Rentao; Han, Gaige; Schmidt, Martina

2012-01-01

Aspergillus fumigatus is the most prevalent airborne fungal pathogen that induces serious infections in immunocompromised patients. Phospholipases are key enzymes in pathogenic fungi that cleave host phospholipids, resulting in membrane destabilization and host cell penetration. However, knowledge of the impact of phospholipases on A. fumigatus virulence is rather limited. In this study, disruption of the pld gene encoding phospholipase D (PLD), an important member of the phospholipase protein family in A. fumigatus, was confirmed to significantly decrease both intracellular and extracellular PLD activity of A. fumigatus. The pld gene disruption did not alter conidial morphological characteristics, germination, growth, and biofilm formation but significantly suppressed the internalization of A. fumigatus into A549 epithelial cells without affecting conidial adhesion to epithelial cells. Importantly, the suppressed internalization was fully rescued in the presence of 100 μM phosphatidic acid, the PLD product. Indeed, complementation of pld restored the PLD activity and internalization capacity of A. fumigatus. Phagocytosis of A. fumigatus conidia by J774 macrophages was not affected by the absence of the pld gene. Pretreatment of conidia with 1-butanol and a specific PLD inhibitor decreased the internalization of A. fumigatus into A549 epithelial cells but had no effect on phagocytosis by J774 macrophages. Finally, loss of the pld gene attenuated the virulence of A. fumigatus in mice immunosuppressed with hydrocortisone acetate but not with cyclophosphamide. These data suggest that PLD of A. fumigatus regulates its internalization into lung epithelial cells and may represent an important virulence factor for A. fumigatus infection. PMID:22083709

Antisense suppression of phospholipase D alpha retards abscisic acid- and ethylene-promoted senescence of postharvest Arabidopsis leaves.

PubMed Central

Fan, L; Zheng, S; Wang, X

1997-01-01

Membrane disruption has been proposed to be a key event in plant senescence, and phospholipase D (PLD; EC 3.1.4.4) has been thought to play an important role in membrane deterioration. We recently cloned and biochemically characterized three different PLDs from Arabidopsis. In this study, we investigated the role of the most prevalent phospholipid-hydrolyzing enzyme, PLD alpha, in membrane degradation and senescence in Arabidopsis. The expression of PLD alpha was suppressed by introducing a PLD alpha antisense cDNA fragment into Arabidopsis. When incubated with abscisic acid and ethylene, leaves detached from the PLD alpha-deficient transgenic plants showed a slower rate of senescence than did those from wild-type and transgenic control plants. The retardation of senescence was demonstrated by delayed leaf yellowing, lower ion leakage, greater photosynthetic activity, and higher content of chlorophyll and phospholipids in the PLD alpha antisense leaves than in those of the wild type. Treatment of detached leaves with abscisic acid and ethylene stimulated PLD alpha expression, as indicated by increases in PLD alpha mRNA, protein, and activity. In the absence of abscisic acid and ethylene, however, detached leaves from the PLD alpha-deficient and wild-type plants showed a similar rate of senescence. In addition, the suppression of PLD alpha did not alter natural plant growth and development. These data suggest that PLD alpha is an important mediator in phytohormone-promoted senescence in detached leaves but is not a direct promoter of natural senescence. The physiological relevance of these findings is discussed. PMID:9437863

Linear-quadratic dose kinetics or dose-dependent repair/misrepair

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braby, L.A.; Nelson, J.M.

1991-09-01

Models for the response of cells exposed to low LET radiation can be grouped into three general types on the basis of assumptions about the nature of the interaction which results in the shoulder of the survival curve. The three forms of interaction are (1) sublethal damage becoming lethal, (2) potentially lethal damage becoming irreparable, and (3) potentially lethal damage saturating'' a repair system. The effects that these three forms of interaction would have on the results of specific types of experiments are investigated. Comparisons with experimental results indicate that only the second type is significant in determining the responsemore » of typical cultured mammalian cells. 5 refs., 2 figs.« less

THE UNCOVERING OF A NOVEL REGULATORY MECHANISM FOR PLD2: FORMATION OF A TERNARY COMPLEX WITH PROTEIN TYROSINE PHOSPHATASE PTP1B AND GROWTH FACTOR RECEPTOR-BOUND PROTEIN GRB2

PubMed Central

Horn, Jeff; Lopez, Isabel; Miller, Mill; Gomez-Cambronero, Julian

2011-01-01

The regulation of PLD2 activation is poorly understood at present. Transient transfection of COS-7 with a mycPLD2 construct results in elevated levels of PLD2 enzymatic activity and tyrosyl phosphorylation. To investigate whether this phosphorylation affects PLD2 enzymatic activity, anti-myc immunoprecipitates were treated with recombinant protein tyrosine phosphatase PTP1B. Surprisingly, lipase activity and PY levels both increased over a range of PTP1B concentrations. These increases occurred in parallel to a measurable PTP1B-associated phosphatase activity. Inhibitor studies demonstrated that an EGF-receptor type kinase is involved in phosphorylation. In a COS-7 cell line created in the laboratory that stably expressed myc-PLD2, PTP1B induced a robust (>6-fold) augmentation of myc-PLD2 phosphotyrosine content. The addition of growth factor receptor-bound protein 2 (Grb2) to cell extracts also elevated PY levels of myc-PLD (>10-fold). Systematic co-immunoprecipitation-immunoblotting experiments pointed at a physical association between PLD2, Grb2 and PTP1B in both physiological conditions and in overexpressed cells. This is the first report of a demonstration of the mammalian isoform PLD2 existing in a ternary complex with a protein tyrosine phosphatase, PTP1b, and the docking protein Grb2 which greatly enhances tyrosyl phosphorylation of the lipase. PMID:15896299

Elevation of oleate-activated phospholipase D activity during thymic atrophy

PubMed Central

Lee, Youngkyun; Song, Soo-Mee; Park, Heung Soon; Kim, Sungyeol; Koh, Eun-Hee; Choi, Myung Sun; Choi, Myung-Un

2002-01-01

Various phospholipases are thought to be associated with the in vitro apoptosis of thymocytes. In the present study, the in vivo phospholipase D (PLD) activity of rat thymus was studied after whole-body X-irradiation or injection of dexamethasone (DEX). Using exogenous [14C]dipalmitoyl phosphatidylcholine (PC) as the substrate, an elevation of oleate-activated PLD activity was observed during thymic atrophy. The activity increases were sevenfold at 48 hr after 5-Gy irradiation and fourfold at 72 hr after injection of 5 mg/kg DEX. The elevation of PLD activity appeared to parallel extensive thymus shrinkage. An increased level of thymic phosphatidic acid (PA), the presumed physiological product of PLD action on PC, was also detected. By comparing the acyl chains of PA with those of other phospholipids, PA appeared to originate from PC. To assess the role of PLD during thymic atrophy, thymocytes and stromal cells were isolated. Although thymocytes themselves exhibited significant PLD activation, the major elevation in PLD activity (greater than fourfold) was found in isolated stromal cells. PLD was also activated during in vitro phagocytosis of apoptotic thymocytes by the macrophage-like cell line P388D1. This in vitro phagocytosis was significantly inhibited by PLD action blockers, such as 2,3-diphosphoglycerate and 1-butanol. These observations strongly suggest that the alteration of oleate-activated PLD activity is part of an in vivo event in the progression of thymic atrophy, including phagocytic clearance of apoptotic thymocytes. PMID:12460188

Phospholipase D1 increases Bcl-2 expression during neuronal differentiation of rat neural stem cells.

PubMed

Park, Shin-Young; Ma, Weina; Yoon, Sung Nyo; Kang, Min Jeong; Han, Joong-Soo

2015-01-01

We studied the possible role of phospholipase D1 (PLD1) in the neuronal differentiation, including neurite formation of neural stem cells. PLD1 protein and PLD activity increased during neuronal differentiation. Bcl-2 also increased. Downregulation of PLD1 by transfection with PLD1 siRNA or a dominant-negative form of PLD1 (DN-PLD1) inhibited both neurite outgrowth and Bcl-2 expression. PLD activity was dramatically reduced by a PLCγ (phospholipase Cγ) inhibitor (U73122), a Ca(2+)chelator (BAPTA-AM), and a PKCα (protein kinase Cα) inhibitor (RO320432). Furthermore, treatment with arachidonic acid (AA) which is generated by the action of PLA2 (phospholipase A2) on phosphatidic acid (a PLD1 product), increased the phosphorylation of p38 MAPK and CREB, as well as Bcl-2 expression, indicating that PLA2 is involved in the differentiation process resulting from PLD1 activation. PGE2 (prostaglandin E2), a cyclooxygenase product of AA, also increased during neuronal differentiation. Moreover, treatment with PGE2 increased the phosphorylation of p38 MAPK and CREB, as well as Bcl-2 expression, and this effect was inhibited by a PKA inhibitor (Rp-cAMP). As expected, inhibition of p38 MAPK resulted in loss of CREB activity, and when CREB activity was blocked with CREB siRNA, Bcl-2 production also decreased. We also showed that the EP4 receptor was required for the PKA/p38MAPK/CREB/Bcl-2 pathway. Taken together, these observations indicate that PLD1 is activated by PLCγ/PKCα signaling and stimulate Bcl-2 expression through PLA2/Cox2/EP4/PKA/p38MAPK/CREB during neuronal differentiation of rat neural stem cells.

Pivotal role of phospholipase D1 in tumor necrosis factor-α-mediated inflammation and scar formation after myocardial ischemia and reperfusion in mice.

PubMed

Schönberger, Tanja; Jürgens, Tobias; Müller, Julia; Armbruster, Nicole; Niermann, Christina; Gorressen, Simone; Sommer, Jan; Tian, Huasong; di Paolo, Gilbert; Scheller, Jürgen; Fischer, Jens W; Gawaz, Meinrad; Elvers, Margitta

2014-09-01

Myocardial inflammation is critical for ventricular remodeling after ischemia. Phospholipid mediators play an important role in inflammatory processes. In the plasma membrane they are degraded by phospholipase D1 (PLD1). PLD1 was shown to be critically involved in ischemic cardiovascular events. Moreover, PLD1 is coupled to tumor necrosis factor-α signaling and inflammatory processes. However, the impact of PLD1 in inflammatory cardiovascular disease remains elusive. Here, we analyzed the impact of PLD1 in tumor necrosis factor-α-mediated activation of monocytes after myocardial ischemia and reperfusion using a mouse model of myocardial infarction. PLD1 expression was highly up-regulated in the myocardium after ischemia/reperfusion. Genetic ablation of PLD1 led to defective cell adhesion and migration of inflammatory cells into the infarct border zone 24 hours after ischemia/reperfusion injury, likely owing to reduced tumor necrosis factor-α expression and release, followed by impaired nuclear factor-κB activation and interleukin-1 release. Moreover, PLD1 was found to be important for transforming growth factor-β secretion and smooth muscle α-actin expression of cardiac fibroblasts because myofibroblast differentiation and interstitial collagen deposition were altered in Pld1(-/-) mice. Consequently, infarct size was increased and left ventricular function was impaired 28 days after myocardial infarction in Pld1(-/-) mice. Our results indicate that PLD1 is crucial for tumor necrosis factor-α-mediated inflammation and transforming growth factor-β-mediated collagen scar formation, thereby augmenting cardiac left ventricular function after ischemia/reperfusion. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Study of thin film growth kinetics of homoepitaxy by molecular beam epitaxy and pulsed laser deposition

NASA Astrophysics Data System (ADS)

Shin, Byungha

This thesis presents an extensive study of the growth kinetics during low temperature homoepitaxy by Molecular Beam Epitaxy (MBE) and Pulsed Laser Deposition (PLD) of our model system Ge(001). The range of the study covers from the sub-monolayer (sub-ML) regime to the later stage where film thickness amounts to a few thousand MLs; it also covers epitaxial breakdown in which epitaxial growth is no longer sustained and the growing phase becomes amorphous. First, we have conducted a systematic investigation of the phase shift of the RHEED intensity oscillations during Ge(001) homoepitaxy MBE for a wide range of diffraction conditions. We conclude that the phase shift is caused by the overlap of the specular spot and the Kikuchi features, in contrast to models involving dynamical scattering theory for the phase shift. We have studied the sub-ML growth of Ge(001) homoepitaxy by MBE at low temperatures using RHEED intensity oscillations obtained for a range of low incidence angles where the influence of the dynamical nature of electron scattering such as the Kikuchi features is minimized. We have developed a new model for RHEED specular intensity that includes the diffuse scattering off surface steps and the layer interference between terraces of different heights using the kinematic approximation. By using the model to interpret the measured RHEED intensity, we find the evolution of the coverage of the first 2--3 layers, from which we infer the ES barrier height to be 0.077 +/- 0.014 eV. Finally, using a dual MBE-PLD UHV chamber, we have conducted experiments under identical thermal, background, and surface preparation conditions to compare Ge(001) homoepitaxial growth morphology in PLD and MBE at low temperatures. To isolate the effect of kinetic energy of depositing species during PLD, we varied the average kinetic energy: ˜450 eV in PLD-HKE, ˜300 eV in PLD-LKE, and <1 eV in PLD-TH. At 150°C, we find that in PLD-LKE and in MBE the film morphology evolves in a similar fashion: initially irregularly shaped mounds form, followed by pyramidal mounds with edges of the square-base along <100> directions. The areal feature density is higher for PLD films than for MBE films grown at the same average growth rate and temperature. Furthermore, the dependence upon film thickness of roughness and feature separation differ for PLD and MBE. The thicknesses at which epitaxial breakdown occurs are ranked in the order PLD-HKE > PLD-LKE > MBE. At 100°C, PLD-LKE and MBE follow the same morphology evolution as at 150°C. The epitaxial thicknesses are ranked in the order PLD-LKE > MBE > PLD-TH; additionally, the surface is smoother in PLD-LKE than in MBE. Together, these results convincingly demonstrate that the enhancement of epitaxial growth---the reduction in roughness and the delay of epitaxial breakdown---are due to the kinetic energy of depositing species in PLD. To study the relaxation behavior, we varied the repetition rate from 5 Hz to 20 Hz in PLD-LKE at 100°C. However, we find no systematic effect on surface roughness by varying the repetition rate. This result is consistent with an investigation on the sub-ML growth regime of PLD-LKE by monitoring the intensity variations of the RHEED specular spot.

FIRST RESULTS ON X-RAY-INDUCED GENETIC DAMAGE IN ARTEMIA SALINA LEACH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Metalli, P.; Ballardin, E.

1962-01-01

Prophase oocytes of diploid and tetraploid pantenogenetic Antemia salina were x irradiated with 1000 r and damage was scored as oocyte or embryo lethal mutations at the first (X/sub 1/) and at the second (X/sub 2/) generations after irradiation. Dominant lethality shown at X/sub 1/ was much greater for the diploid strain than for the tetraploid; lethality observed at X/sub 2/ was increased with respect to X/sub 1/ in the diploid strain, while in the tetraploid it remained unmodified. (auth)

Interchromosomal Associations that Alter Nf1 Gene Expression can Modify Clinical Manifestations of Neurofibromatosis 1

DTIC Science & Technology

2008-09-01

intracellular portion of the EGFR and stimulates PLD2 activity. PLD2 catalyzes the hydrolysis of phosphatidylcholine (PC) to phosphatidic acid (PA) and...ARF4 can bind with EGFR and activate PLD2. The phosphatidic acid (PA) produced by PLD2 can recruit Sos, which can then colocalize and activate

Durability and Damage Tolerance of Bismaleimide Composites. Volume 1. Technical Report

DTIC Science & Technology

1988-06-01

Test Setup Figure 1-14, Failed Loaded Holo Static Spoifton 106 mru FaJIus Stma. FuMr Materal Spwima anT VPIU h Kok Fo Faflurep t PldN Stromsym EVIM hm...Environrnental Chamber tot ETW TesI $ 1 36 12.5 x lOft.Ibs x 7ft-lbsI- __ 8.5 14ft-bs Figure 146. Outer Mold Une Impact Locations and Eery -Levela 5.3.5

Radiosensitizing effects of neem (Azadirachta indica) oil.

PubMed

Kumar, Ashok; Rao, A R; Kimura, H

2002-02-01

Radiosensitization by neem oil was studied using Balbc/3T3 cells and SCID cells. Neem oil enhanced the radiosensitivity of the cells when applied both during and after x-irradiation under aerobic conditions. Neem oil completely inhibited the repair of sublethal damage and potentially lethal damage repair in Balbc/3T3 cells. The cytofluorimeter data show that neem oil treatment before and after x-irradiation reduced the G(2) + M phase, thus inhibiting the expression of the radiation induced arrest of cells in the G(2) phase of the cell cycle. However, SCIK cells (derived from the SCID mouse), deficient in DSB repair, treated with neem oil did not show any enhancement in the radiosensitivity. There was no effect of neem oil on SLD repair or its inhibition in SCIK cells. These results suggest that neem oil enhanced the radiosensitivity of cells by interacting with residual damage after x-irradiation, thereby converting the sublethal damage or potentially lethal damage into lethal damage, inhibiting the double-strand break repair or reducing the G(2) phase of the cell cycle. Copyright 2002 John Wiley & Sons, Ltd.

Phospholipase D2 (PLD2) shortens the time required for myeloid leukemic cell differentiation: mechanism of action.

PubMed

Di Fulvio, Mauricio; Frondorf, Kathleen; Henkels, Karen M; Grunwald, William C; Cool, David; Gomez-Cambronero, Julian

2012-01-02

Cell differentiation is compromised in acute leukemias. We report that mammalian target of rapamycin (mTOR) and S6 kinase (S6K) are highly expressed in the undifferentiated promyelomonocytic leukemic HL-60 cell line, whereas PLD2 expression is minimal. The expression ratio of PLD2 to mTOR (or to S6K) is gradually inverted upon in vitro induction of differentiation toward the neutrophilic phenotype. We present three ways that profoundly affect the kinetics of differentiation as follows: (i) simultaneous overexpression of mTOR (or S6K), (ii) silencing of mTOR via dsRNA-mediated interference or inhibition with rapamycin, and (iii) PLD2 overexpression. The last two methods shortened the time required for differentiation. By determining how PLD2 participates in cell differentiation, we found that PLD2 interacts with and activates the oncogene Fes/Fps, a protein-tyrosine kinase known to be involved in myeloid cell development. Fes activity is elevated with PLD2 overexpression, phosphatidic acid or phosphatidylinositol bisphosphate. Co-immunoprecipitation indicates a close PLD2-Fes physical interaction that is negated by a Fes-R483K mutant that incapacitates its Src homology 2 domain. All these suggest for the first time the following mechanism: mTOR/S6K down-regulation→PLD2 overexpression→PLD2/Fes association→phosphatidic acid-led activation of Fes kinase→granulocytic differentiation. Differentiation shortening could have a clinical impact on reducing the time of return to normalcy of the white cell counts after chemotherapy in patients with acute promyelocytic leukemia.

Arterial Spin Labeling Perfusion Magnetic Resonance Image with Dual Postlabeling Delay: A Correlative Study with Acetazolamide Loading (123)I-Iodoamphetamine Single-Photon Emission Computed Tomography.

PubMed

Haga, Sei; Morioka, Takato; Shimogawa, Takafumi; Akiyama, Tomoaki; Murao, Kei; Kanazawa, Yuka; Sayama, Tetsuro; Arakawa, Shuji

2016-01-01

Perfusion magnetic resonance image with arterial spin labeling (ASL) provides a completely noninvasive measurement of cerebral blood flow (CBF). However, arterial transient times can have a marked effect on the ASL signal. For example, a single postlabeling delay (PLD) of 1.5 seconds underestimates the slowly streaming collateral pathways that maintain the cerebrovascular reserve (CVR). To overcome this limitation, we developed a dual PLD method. A dual PLD method of 1.5  and 2.5 seconds was compared with (123)I-iodoamphetamine single-photon emission computed tomography with acetazolamide loading to assess CVR in 10 patients with steno-occlusive cerebrovascular disease. In 5 cases (Group A), dual PLD-ASL demonstrated low CBF with 1.5-second PLD in the target area, whereas CBF was improved with 2.5-second PLD. In the other 5 cases (Group B), dual PLD-ASL depicted low CBF with 1.5-second PLD, and no improvement in CBF with 2.5-second PLD in the target area was observed. On single-photon emission computed tomography, CVR was maintained in Group A but decreased in Group B. Although dual PLD methods may not be a completely alternative test for (123)I-iodoamphetamine single-photon emission computed tomography with acetazolamide loading, it is a feasible, simple, noninvasive, and repeatable technique for assessing CVR, even when employed in a routine clinical setting. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Phospholipase D1 downregulation by α-synuclein: Implications for neurodegeneration in Parkinson's disease.

PubMed

Conde, Melisa A; Alza, Natalia P; Iglesias González, Pablo A; Scodelaro Bilbao, Paola G; Sánchez Campos, Sofía; Uranga, Romina M; Salvador, Gabriela A

2018-06-01

We have previously shown that phospholipase D (PLD) pathways have a role in neuronal degeneration; in particular, we found that PLD activation is associated with synaptic injury induced by oxidative stress. In the present study, we investigated the effect of α-synuclein (α-syn) overexpression on PLD signaling. Wild Type (WT) α-syn was found to trigger the inhibition of PLD1 expression as well as a decrease in ERK1/2 phosphorylation and expression levels. Moreover, ERK1/2 subcellular localization was shown to be modulated by WT α-syn in a PLD1-dependent manner. Indeed, PLD1 inhibition was found to alter the neurofilament network and F-actin distribution regardless of the presence of WT α-syn. In line with this, neuroblastoma cells expressing WT α-syn exhibited a degenerative-like phenotype characterized by a marked reduction in neurofilament light subunit (NFL) expression and the rearrangement of the F-actin organization, compared with either the untransfected or the empty vector-transfected cells. The gain of function of PLD1 through the overexpression of its active form had the effect of restoring NFL expression in WT α-syn neurons. Taken together, our findings reveal an unforeseen role for α-syn in PLD regulation: PLD1 downregulation may constitute an early mechanism in the initial stages of WT α-syn-triggered neurodegeneration. Copyright © 2018 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Chunfa, E-mail: chunfa.huang@case.edu; Department of Medicine, Case Western Reserve University; Rammelkamp Center for Research and Education, MetroHealth System Campus, Cleveland, OH 44106

The glomerular capillary wall, composed of endothelial cells, the glomerular basement membrane and the podocytes, is continually subjected to hemodynamic force arising from tractional stress due to blood pressure and shear stress due to blood flow. Exposure of glomeruli to abnormal hemodynamic force such as hyperfiltration is associated with glomerular injury and progressive renal disease, and the conversion of mechanical stimuli to chemical signals in the regulation of the process is poorly understood in podocytes. By examining DNA fragmentation, apoptotic nuclear changes and cytochrome c release, we found that shear stress induced cell apoptosis in cultured podocytes. Meanwhile, podocytes exposedmore » to shear stress also stimulated c-Src phosphorylation, phospholipase D (PLD) activation and mammalian target of rapamycin (mTOR) signaling. Using the antibodies against c-Src, PLD{sub 1}, and PLD{sub 2} to perform reciprocal co-immunoprecipitations and in vitro PLD activity assay, our data indicated that c-Src interacted with and activated PLD{sub 1} but not PLD{sub 2}. The inhibition of shear stress-induced c-Src phosphorylation by PP{sub 2} (a specific inhibitor of c-Src kinase) resulted in reduced PLD activity. Phosphatidic acid, produced by shear stress-induced PLD activation, stimulated mTOR signaling, and caused podocyte hypertrophy and apoptosis.« less

Detection of choline and phosphatidic acid (PA) catalyzed by phospholipase D (PLD) using MALDI-QIT-TOF/MS with 9-aminoacridine matrix.

PubMed

Park, Kyung-Eui; Kim, Jun-Dal; Nagashima, Yusuke; Kako, Koichiro; Daitoku, Hiroaki; Matsui, Motoki; Park, Gwi Gun; Fukamizu, Akiyoshi

2014-01-01

Phospholipase D (PLD) catalyzes the hydrolysis of phosphatidylcholine (PC), the most abundant phospholipids of plasma membrane, resulting in the production of choline and phosphatidic acid (PA). Choline is a precursor of the neurotransmitter acetylcholine, whereas PA functions as an intracellular lipid mediator of diverse biological functions. For assessing PLD activity in vitro, PLD-derived choline has been often analyzed with radioactive or non-radioactive methods. In this study, we have developed a new method for detecting choline and PA with MALDI-QIT-TOF/MS by using 9-aminoacridine as a matrix. The standard calibration curves showed that choline and PA could be detected with linearity over the range from 0.05 and 1 pmol, respectively. Importantly, this method enables the concomitant detection of choline and PA as a reaction product of PC hydrolysis by PLD2 proteins. Thus, our simple and direct method would be useful to characterize the enzymatic properties of PLD, thereby providing insight into mechanisms of PLD activation.

Action of caffeine on x-irradiated HeLa cells. V. Identity of the sector of cells that expresses potentially lethal damage in G/sub 1/ and G/sub 2/

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beetham, K.L.; Tolmach, L.J.

1982-07-01

When HeLa S3 cells are irradiated in early G/sub 1/ with 4 Gy of 220-kV x rays and are then incubated in growth medium containing up to 5 mM caffeine, survival is reduced (as reported previously), reaching a concentration-dependent plateau. Cell killing presumably occurs as a result of the fixation of a portion of the potentially lethal damage the cells contain. These cells respond to continued treatment with caffeine at concentrations greater than 2 mM during S, but less so than during G/sub 1/. When they reach G/sub 2/ arrest, however, extensive cell killing again occurs (reported previously), presumably alsomore » the result of potentially lethal damage fixation. G/sub 1/-irradiated cultures that are treated with caffeine either continuously at a concentration in the range 1 to 5 mM, or at 10 mM for 8 hr and subsequently with the low concentration, achieve the same survival level in G/sub 2/, provided that the potentially lethal damage is not repaired during G/sub 1/ and S. Repair seems to be completely inhibited in the presence of 3 to 4 mM caffeine. The results indicate that fixation of potentially lethal damage occurs in the same sector of cells in G/sub 1/ and G/sub 2/, suggesting that the same cellular lesion gives rise to cell killing in the two phases.« less

Genome-Wide Comparative Analysis of the Phospholipase D Gene Families among Allotetraploid Cotton and Its Diploid Progenitors

PubMed Central

Tang, Kai; Dong, Chun-Juan; Liu, Jin-Yuan

2016-01-01

In this study, 40 phospholipase D (PLD) genes were identified from allotetraploid cotton Gossypium hirsutum, and 20 PLD genes were examined in diploid cotton Gossypium raimondii. Combining with 19 previously identified Gossypium arboreum PLD genes, a comparative analysis was performed among the PLD gene families among allotetraploid and two diploid cottons. Based on the orthologous relationships, we found that almost each G. hirsutum PLD had a corresponding homolog in the G. arboreum and G. raimondii genomes, except for GhPLDβ3A, whose homolog GaPLDβ3 may have been lost during the evolution of G. arboreum after the interspecific hybridization. Phylogenetic analysis showed that all of the cotton PLDs were unevenly classified into six numbered subgroups: α, β/γ, δ, ε, ζ and φ. An N-terminal C2 domain was found in the α, β/γ, δ and ε subgroups, while phox homology (PX) and pleckstrin homology (PH) domains were identified in the ζ subgroup. The subgroup φ possessed a single peptide instead of a functional domain. In each phylogenetic subgroup, the PLDs showed high conservation in gene structure and amino acid sequences in functional domains. The expansion of GhPLD and GrPLD gene families were mainly attributed to segmental duplication and partly attributed to tandem duplication. Furthermore, purifying selection played a critical role in the evolution of PLD genes in cotton. Quantitative RT-PCR documented that allotetraploid cotton PLD genes were broadly expressed and each had a unique spatial and developmental expression pattern, indicating their functional diversification in cotton growth and development. Further analysis of cis-regulatory elements elucidated transcriptional regulations and potential functions. Our comparative analysis provided valuable information for understanding the putative functions of the PLD genes in cotton fiber. PMID:27213891

PLD2 has both enzymatic and cell proliferation-inducing capabilities, that are differentially regulated by phosphorylation and dephosphorylation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henkels, Karen M.; Short, Stephen; Peng, Hong-Juan

2009-11-13

Phospholipase D2 (PLD2) overexpression in mammalian cells results in cell transformation. We have hypothesized that this is due to an increase of de novo DNA synthesis. We show here that overexpression of PLD2-WT leads to an increased DNA synthesis, as measured by the expression levels of the proliferation markers PCNA, p27{sup KIP1} and phospho-histone-3. The enhancing effect was even higher with phosphorylation-deficient PLD2-Y179F and PLD2-Y511F mutants. The mechanism for this did not involve the enzymatic activity of the lipase, but, rather, the presence of the protein tyrosine phosphatase CD45, as silencing with siRNA for CD45 abrogated the effect. The twomore » Y{yields}F mutants had in common a YxN consensus site that, in the phosphorylated counterparts, could be recognized by SH2-bearing proteins, such as Grb2. Even though Y179F and Y511F cannot bind Grb2, they could still find other protein partners, one of which, we have reasoned, could be CD45 itself. Affinity purified PLD2 is indeed activated by Grb2 and deactivated by CD45 in vitro. We concluded that phosphorylated PLD2, aided by Grb2, mediates lipase activity, whereas dephosphorylated PLD2 mediates an induction of cell proliferation, and the specific residues involved in this newly discovered regulation of PLD2 are Y{sup 179} and Y{sup 511}.« less

Identification of a novel phospholipase D with high transphosphatidylation activity and its application in synthesis of phosphatidylserine and DHA-phosphatidylserine.

PubMed

Mao, Xiangzhao; Liu, Qianqian; Qiu, Yongqian; Fan, Xiaoqin; Han, Qingqing; Liu, Yanjun; Zhang, Lujia; Xue, Changhu

2017-05-10

Phosphatidylserine (PS) and docosahexaenoic acid-phosphatidylserine (DHA-PS) have significant nutritional and biological functions, which are extensively used in functional food industries. Phospholipase D (PLD)-mediated transphosphatidylation of phosphatidylcholine (PC) or DHA-PC with l-serine, is an effective method for PS and DHA-PS preparation. However, because of the hydrolysis activity of PLD, PC and DHA-PC would be converted to the undesirable byproduct, phosphatidic acid (PA) and DHA-PA. In this study, a novel phospholipase D (PLD a2 ) was firstly cloned from Acinetobacter radioresistens a2 with high transphosphatidylation activity and no hydrolysis activity. In the PLD-catalyzed synthesis process (12h), both the transphosphatidylation conversion rate and selectivity of PS and DHA-PS were about 100%, which is the only PLD enzyme reported with this superiority up till now. In comparison with the majority of other known PLDs, PLD a2 exerted the highest activity at neutral pH, and it was stable from pH 4.0 to pH 9.0. In addition, PLD a2 had excellent thermal stability, with an optimum reaction temperature of 40°C and keeping more than 80% activity from 20°C to 60°C. The high catalytic selectivity mechanism of PLD a2 was explained by utilizing homology modeling, two-step docking, and binding energy and conformation analysis. PLD a2 ensured a stable supply of the biocatalyst with its most preponderant transphosphatidylation activity and PS selectivity, and had great potential in phospholipids industrial production. Copyright © 2017 Elsevier B.V. All rights reserved.

Rare Variants in PLD3 Do Not Affect Risk for Early‐Onset Alzheimer Disease in a European Consortium Cohort

PubMed Central

Cacace, Rita; Van den Bossche, Tobi; Engelborghs, Sebastiaan; Geerts, Nathalie; Laureys, Annelies; Dillen, Lubina; Graff, Caroline; Thonberg, Håkan; Chiang, Huei‐Hsin; Pastor, Pau; Ortega‐Cubero, Sara; Pastor, Maria A.; Diehl‐Schmid, Janine; Alexopoulos, Panagiotis; Benussi, Luisa; Ghidoni, Roberta; Binetti, Giuliano; Nacmias, Benedetta; Sorbi, Sandro; Sanchez‐Valle, Raquel; Lladó, Albert; Gelpi, Ellen; Almeida, Maria Rosário; Santana, Isabel; Tsolaki, Magda; Koutroumani, Maria; Clarimon, Jordi; Lleó, Alberto; Fortea, Juan; de Mendonça, Alexandre; Martins, Madalena; Borroni, Barbara; Padovani, Alessandro; Matej, Radoslav; Rohan, Zdenek; Vandenbulcke, Mathieu; Vandenberghe, Rik; De Deyn, Peter P.; Cras, Patrick; van der Zee, Julie; Sleegers, Kristel

2015-01-01

ABSTRACT Rare variants in the phospholipase D3 gene (PLD3) were associated with increased risk for late‐onset Alzheimer disease (LOAD). We identified a missense mutation in PLD3 in whole‐genome sequence data of a patient with autopsy confirmed Alzheimer disease (AD) and onset age of 50 years. Subsequently, we sequenced PLD3 in a Belgian early‐onset Alzheimer disease (EOAD) patient (N = 261) and control (N = 319) cohort, as well as in European EOAD patients (N = 946) and control individuals (N = 1,209) ascertained in different European countries. Overall, we identified 22 rare variants with a minor allele frequency <1%, 20 missense and two splicing mutations. Burden analysis did not provide significant evidence for an enrichment of rare PLD3 variants in EOAD patients in any of the patient/control cohorts. Also, meta‐analysis of the PLD3 data, including a published dataset of a German EOAD cohort, was not significant (P = 0.43; OR = 1.53, 95% CI 0.60–3.31). Consequently, our data do not support a role for PLD3 rare variants in the genetic etiology of EOAD in European EOAD patients. Our data corroborate the negative replication data obtained in LOAD studies and therefore a genetic role of PLD3 in AD remains to be demonstrated. PMID:26411346

Delineating the requirements for spontaneous DNA damage resistance pathways in genome maintenance and viability in Saccharomyces cerevisiae.

PubMed

Morey, Natalie J; Doetsch, Paul W; Jinks-Robertson, Sue

2003-06-01

Cellular metabolic processes constantly generate reactive species that damage DNA. To counteract this relentless assault, cells have developed multiple pathways to resist damage. The base excision repair (BER) and nucleotide excision repair (NER) pathways remove damage whereas the recombination (REC) and postreplication repair (PRR) pathways bypass the damage, allowing deferred removal. Genetic studies in yeast indicate that these pathways can process a common spontaneous lesion(s), with mutational inactivation of any pathway increasing the burden on the remaining pathways. In this study, we examine the consequences of simultaneously compromising three or more of these pathways. Although the presence of a functional BER pathway alone is able to support haploid growth, retention of the NER, REC, or PRR pathway alone is not, indicating that BER is the key damage resistance pathway in yeast and may be responsible for the removal of the majority of either spontaneous DNA damage or specifically those lesions that are potentially lethal. In the diploid state, functional BER, NER, or REC alone can support growth, while PRR alone is insufficient for growth. In diploids, the presence of PRR alone may confer a lethal mutation load or, alternatively, PRR alone may be insufficient to deal with potentially lethal, replication-blocking lesions.

[Purification, characterization and application of ε-poly-L. lysine- degrading enzyme from Streptomyces sp. M-Z18 ].

PubMed

Liu, Qingrui; Chen, Xusheng; Zeng, Xin; Han, Dai; Mao, Zhonggui

2014-09-04

[OBJECTIVE] The ε-poly-L-lysine-degrading enzyme (Pld) derived from Streptomyces sp. M-Z18 was purified and characterized. Furthermore, Pld was used to produce the low polymerization of ε-poly-L-lysine (ε-PL). [METHODS] Pld was purified to electrophoretical homogeneity through HiTrapTM Butyl HP hydrophobic chromatography after pretreated by ultrasonic and NaSCN dissolving. Subsequently, enzymatic characteristics, kinetic parameters and the time profile of ε-PL degradation by the purified Pld were studied. Meanwhile, we examined the effect of ε-PL with different degrees of polymerization on the minimal inhibitory concentration of bacteria and fungi. [RESULTS] Pld was purified to homogeneity with a final fold of 80.4 and an overall yield of 59.3%. The optimal temperature and pH for the purified Pld were 370C and 7. 0, respectively. Moreover, the Km with L-lysyl-p-nitroanilide as substrate was calculated to be 0. 621 mmol/L, and the Vmax was 701. 16 nmol/min.mg. Pld was stable in the range of pH 7. 0 - 10. 0, and temperature up to 500 C, respectively. Time profile of ε-PL degradation by the purified Pld indicated that Pld catalyzed endo-type degradation of ε- PL. The experiments of minimal inhibitory showed that ε-PL with high degree of polymerization (30 - 35) had a superior antibacterial effect on bacteria and the low degree of polymerization ε-PL (8 -20) had a better antibacterial effect on yeasts. However, ε-PL with various degrees of polymerization had a poor antibacterial effect on mould. [ CONCLUSION] The present result showed that an endo-type Pld from ε-PL-producing strain was purified. Meanwhile, it is proved that ε-PL with different degrees of polymerization have exhibited significant different antibacterial effects on microorganism.

Dynamic Scaling and Island Growth Kinetics in Pulsed Laser Deposition of SrTiO 3

DOE PAGES

Eres, Gyula; Tischler, J. Z.; Rouleau, C. M.; ...

2016-11-11

We use real-time diffuse surface x-ray diffraction to probe the evolution of island size distributions and its effects on surface smoothing in pulsed laser deposition (PLD) of SrTiO 3. In this study, we show that the island size evolution obeys dynamic scaling and two distinct regimes of island growth kinetics. Our data show that PLD film growth can persist without roughening despite thermally driven Ostwald ripening, the main mechanism for surface smoothing, being shut down. The absence of roughening is concomitant with decreasing island density, contradicting the prevailing view that increasing island density is the key to surface smoothing inmore » PLD. We also report a previously unobserved crossover from diffusion-limited to attachment-limited island growth that reveals the influence of nonequilibrium atomic level surface transport processes on the growth modes in PLD. We show by direct measurements that attachment-limited island growth is the dominant process in PLD that creates step flowlike behavior or quasistep flow as PLD “self-organizes” local step flow on a length scale consistent with the substrate temperature and PLD parameters.« less

Dynamic Scaling and Island Growth Kinetics in Pulsed Laser Deposition of SrTiO 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eres, Gyula; Tischler, J. Z.; Rouleau, C. M.

We use real-time diffuse surface x-ray diffraction to probe the evolution of island size distributions and its effects on surface smoothing in pulsed laser deposition (PLD) of SrTiO 3. In this study, we show that the island size evolution obeys dynamic scaling and two distinct regimes of island growth kinetics. Our data show that PLD film growth can persist without roughening despite thermally driven Ostwald ripening, the main mechanism for surface smoothing, being shut down. The absence of roughening is concomitant with decreasing island density, contradicting the prevailing view that increasing island density is the key to surface smoothing inmore » PLD. We also report a previously unobserved crossover from diffusion-limited to attachment-limited island growth that reveals the influence of nonequilibrium atomic level surface transport processes on the growth modes in PLD. We show by direct measurements that attachment-limited island growth is the dominant process in PLD that creates step flowlike behavior or quasistep flow as PLD “self-organizes” local step flow on a length scale consistent with the substrate temperature and PLD parameters.« less

Synthesis and Characterization of ZnO/polymer planar heterojunction solar cells

NASA Astrophysics Data System (ADS)

Gutierrez, Leandro; Manners, William; Nabizadeh, Arya; Albers, Patrick; Duran, Jesus; Scudieri, Anthony; Isah, Anne; McDougall, Michael; Sahiner, Mehmet; Wang, Weining

2014-03-01

ZnO/polymer heterojunction has been studied by many groups for its potential application in solar cell, LED, UV photodetection and other applications. However, there are few studies on ZnO/polymer heterojunction by synthesizing ZnO using pulsed laser deposition (PLD). Comparing with other methods, PLD has the advantage of congruent evaporation, and being able to grow high quality thin films at relatively low temperature. In our previous work in pulsed-laser-deposited (PLD) ZnO/PEDOT:PSS heterojunction, correlations between the annealing conditions of pulsed laser deposition and the electrical performance of solar cells have been observed. In this work, we report two new studies: 1) Studies on how the performance of the PLD-ZnO /PEDOT:PSS heterojunction depends on polymer conductivity; 2) Comparison studies on PLD-ZnO/PEDOT:PSS and PLD-ZnO/P3HT heterojunction. We studied how the performance of ZnO/polymer solar cells depend on the polymer work function and conductivities and deposition condition of ZnO. X-ray diffraction (XRD) and scanning electron microscopy were used to characterize the PLD-ZnO film. The correlation between the solar cell electrical performance and the polymer conductivity and pulsed laser deposition conditions will be discussed.

Biological damage induced by ionizing cosmic rays in dry Arabidopsis seeds.

PubMed

Kranz, A R; Bork, U; Bucker, H; Reitz, G

1990-01-01

In September 1987 dry seeds containing embryos of the crucifer plant Arabidopsis thaliana (L.) Heynh, were flown in orbit for 13 days on the Kosmos 1887 satellite. The seeds were fixed on CNd detectors and stored in units of Biorack type I/O. One unit was exposed inside, another one outside the satellite. The temperature profile of the flown seeds inside the satellite was simulated on earth in an identical backup control sample (BC). An additional control (SC) was studied with the original seeds sample. By use of the CNd-detector, HZE-tracks were measured with a PC-assisted microscope. The biological damages were investigated by growing the seeds under controlled climatic conditions. The following biological endpoints of the cosmic radiation damage were studied: germination, radicle length, sublethality, morphological aberrations, flower development, tumorization, embryo lethality inside the siliques. The summarized damage (D) and the mutation frequencies of embyronic lethal genes were calculated. The following results were obtained: the damages increase significantly in orbit at all biological endpoints; germination and fiowerings especially, as well as embryo lethality of fruits and lethal mutation frequency, were maximum mostly for HZE-hit seeds. Additionally, an increase of damage was observed for the seeds of the outside-exposed Biorack in comparison to the inside ones, which was probably caused by less radiation shielding and free space vacuum. The significance of the results obtained is discussed with respect to stress and risk and, thus, the quality of the RBE-factors and heavy ionizing radiation all needed for the very definition of radiation protection standards in space.

Instrumentation to Support the Research Program of Pulsed Laser Deposition of Polymer Nanocomposite Films

DTIC Science & Technology

2015-05-19

ablated the targets in the same spots during the PLD process. The beams quickly created craters in these spots. That led to cracks and rapid (in...nanoparticles in the near-IR range taken with the newly acquired (with the support from the DoD Grant) UV -VIS-NIR Spectrophotometer Cary from Varian. As...reagent film has the capability of recovering from the exposure to very high ammonia concentrations without experiencing any irreversible damage . Based on

RANDOMIZED TRIAL OF PEGYLATED LIPOSOMAL DOXORUBICIN (PLD) PLUS CARBOPLATIN VERSUS CARBOPLATIN IN PLATINUM-SENSITIVE (PS) PATIENTS WITH RECURRENT EPITHELIAL OVARIAN OR PERITONEAL CARCINOMA AFTER FAILURE OF INITIAL PLATINUM-BASED CHEMOTHERAPY (SOUTH WEST ONCOLOGY GROUP PROTOCOL S0200)

PubMed Central

Alberts, David S.; Liu, P. Y.; Wilczynski, Sharon P.; Clouser, Mary C.; Lopez, Ana Maria; Michelin, David P.; Lanzotti, Victor J.; Markman, Maurie

2008-01-01

Objective Because debate continues over the role of combination, platinum-based chemotherapy for platinum sensitive (PS), recurrent ovarian cancer (OC), we compared overall survival (OS), progression-free survival (PFS), confirmed complete response rate and time to treatment failure in this population. Methods Patients with recurrent stage III or IV OC, a progression-free and platinum-free interval of 6- 24 months after first-line platinum-based chemotherapy and up to 12 courses of a non-platinum containing consolidation treatment were eligible. Patients were randomized to IV pegylated liposomal doxorubicin (PLD) (30 mg/m2) plus IV carboplatin (AUC=5 mg/mL × min) once every 4 weeks (PLD arm) or IV carboplatin alone (AUC=5mg/mL × min) once every 4 weeks. Results The PLD arm enrolled 31 patients and the carboplatin alone arm 30 for a total of 61 patients out of 900 planned. Response rates were 67% for the PLD arm and 32% for the carboplatin only arm (Fisher’s exact p=0.02). The estimated median PFS was 12 and 8 months for PLD versus carboplatin alone. The estimated median OS on the PLD arm was 26 months and 18 months on the carboplatin only arm (p=0.02). Twenty-six percent of the patients on the PLD arm reported grade 4 toxicities, all hematological in nature. Conclusion This study was closed early because of slow patient accrual. The response rate, median PFS and OS results are intriguing. These data suggest that there may be an advantage to the PLD plus carboplatin combination treatment in patients with PS, recurrent OC. The regimen should be further tested. PMID:17949799

Pulsed laser diode photoacoustic tomography (PLD-PAT) system for fast in vivo imaging of small animal brain

NASA Astrophysics Data System (ADS)

Upputuri, Paul Kumar; Kalva, Sandeep Kumar; Moothanchery, Mohesh; Pramanik, Manojit

2017-03-01

In recent years, high-repetition rate pulsed laser diode (PLD) was used as an alternative to the Nd:YAG lasers for photoacoustic tomography (PAT). The use of PLD makes the overall PAT system, a low-cost, portable, and high frame rate imaging tool for preclinical applications. In this work, we will present a portable in vivo pulsed laser diode based photoacoustic tomography (PLD-PAT) system. The PLD is integrated inside a circular scanning geometry. The PLD can provide near-infrared ( 803 nm) pulses with pulse duration 136 ns, and pulse energy 1.4 mJ / pulse at 7 kHz repetition rate. The system will be demonstrated for in vivo fast imaging of small animal brain. To enhance the contrast of brain imaging, experiments will be carried out using contrast agents which have strong absorption around laser excitation wavelength. This low-cost, portable small animal brain imaging system could be very useful for brain tumor imaging and therapy.

Rare Variants in PLD3 Do Not Affect Risk for Early-Onset Alzheimer Disease in a European Consortium Cohort.

PubMed

Cacace, Rita; Van den Bossche, Tobi; Engelborghs, Sebastiaan; Geerts, Nathalie; Laureys, Annelies; Dillen, Lubina; Graff, Caroline; Thonberg, Håkan; Chiang, Huei-Hsin; Pastor, Pau; Ortega-Cubero, Sara; Pastor, Maria A; Diehl-Schmid, Janine; Alexopoulos, Panagiotis; Benussi, Luisa; Ghidoni, Roberta; Binetti, Giuliano; Nacmias, Benedetta; Sorbi, Sandro; Sanchez-Valle, Raquel; Lladó, Albert; Gelpi, Ellen; Almeida, Maria Rosário; Santana, Isabel; Tsolaki, Magda; Koutroumani, Maria; Clarimon, Jordi; Lleó, Alberto; Fortea, Juan; de Mendonça, Alexandre; Martins, Madalena; Borroni, Barbara; Padovani, Alessandro; Matej, Radoslav; Rohan, Zdenek; Vandenbulcke, Mathieu; Vandenberghe, Rik; De Deyn, Peter P; Cras, Patrick; van der Zee, Julie; Sleegers, Kristel; Van Broeckhoven, Christine

2015-12-01

Rare variants in the phospholipase D3 gene (PLD3) were associated with increased risk for late-onset Alzheimer disease (LOAD). We identified a missense mutation in PLD3 in whole-genome sequence data of a patient with autopsy confirmed Alzheimer disease (AD) and onset age of 50 years. Subsequently, we sequenced PLD3 in a Belgian early-onset Alzheimer disease (EOAD) patient (N = 261) and control (N = 319) cohort, as well as in European EOAD patients (N = 946) and control individuals (N = 1,209) ascertained in different European countries. Overall, we identified 22 rare variants with a minor allele frequency <1%, 20 missense and two splicing mutations. Burden analysis did not provide significant evidence for an enrichment of rare PLD3 variants in EOAD patients in any of the patient/control cohorts. Also, meta-analysis of the PLD3 data, including a published dataset of a German EOAD cohort, was not significant (P = 0.43; OR = 1.53, 95% CI 0.60-3.31). Consequently, our data do not support a role for PLD3 rare variants in the genetic etiology of EOAD in European EOAD patients. Our data corroborate the negative replication data obtained in LOAD studies and therefore a genetic role of PLD3 in AD remains to be demonstrated. © 2015 The Authors. **Human Mutation published by Wiley Periodicals, Inc.

Intracellular signaling by phospholipase D as a therapeutic target.

PubMed

Steed, P M; Chow, A H

2001-09-01

The pharmaceutical industry has recently focused on intracellular signaling as a means to integrate the multiple facets of complex disease states, such as inflammation, because these pathways respond to numerous extracellular signals and coordinate a collection of cell responses contributing to pathology. One critical aspect of intracellular signaling is regulation of key cell functions by lipid mediators, in particular the generation of a key mediator, phosphatidic acid (PA) via the hydrolysis of phosphatidylcholine by phospholipase D (PLD). Research in this field has intensified, due in part to the recent cloning and partial characterization of the two PLD isoforms in mammalian cells, and this work has contributed significantly to our understanding of events downstream of PA generation. It is these effector functions of PLD activity that make this pathway attractive as a therapeutic target while the biochemical properties of the PLD isozymes make them amenable to small molecule intervention. Recent studies indicate that PA, and its immediate metabolites diacylglycerol and lyso-PA, affect numerous cellular pathways including ligand-mediated secretion, cytoskeletal reorganisations, respiratory burst, prostaglandin release, cell migration, cytokine release, and mitogenesis. This review summarises the data implicating signaling via PLD in these cell functions, obtained from: (i) molecular analyses of PLD/effector interactions, (ii) correlation between PA production and cell responses, (iii) experimental manipulation of PA levels, (iv) inhibition of PLD regulators, and (v) direct inhibition of PA production. The utility of targeting PLD signaling for the treatment of acute/chronic inflammation and other indications is discussed in light of these data.

Pegylated liposomal formulation of doxorubicin overcomes drug resistance in a genetically engineered mouse model of breast cancer.

PubMed

Füredi, András; Szebényi, Kornélia; Tóth, Szilárd; Cserepes, Mihály; Hámori, Lilla; Nagy, Veronika; Karai, Edina; Vajdovich, Péter; Imre, Tímea; Szabó, Pál; Szüts, Dávid; Tóvári, József; Szakács, Gergely

2017-09-10

Success of cancer treatment is often hampered by the emergence of multidrug resistance (MDR) mediated by P-glycoprotein (ABCB1/Pgp). Doxorubicin (DOX) is recognized by Pgp and therefore it can induce therapy resistance in breast cancer patients. In this study our aim was to evaluate the susceptibility of the pegylated liposomal formulation of doxorubicin (PLD/Doxil®/Caelyx®) to MDR. We show that cells selected to be resistant to DOX are cross-resistant to PLD and PLD is also ineffective in an allograft model of doxorubicin-resistant mouse B-cell leukemia. In contrast, PLD was far more efficient than DOX as reflected by a significant increase of both relapse-free and overall survival of Brca1 -/- ;p53 -/- mammary tumor bearing mice. Increased survival could be explained by the delayed onset of drug resistance. Consistent with the higher Pgp levels needed to confer resistance, PLD administration was able to overcome doxorubicin insensitivity of the mouse mammary tumors. Our results indicate that the favorable pharmacokinetics achieved with PLD can effectively overcome Pgp-mediated resistance, suggesting that PLD therapy could be a promising strategy for the treatment of therapy-resistant breast cancer patients. Copyright © 2017 Elsevier B.V. All rights reserved.

[Damage control in field surgery].

PubMed

Samokhvalov, I M; Manukovskiĭ, V A; Badalov, V I; Severin, V V; Golovko, K P; Denisenko, V V

2011-09-01

Damage control surgery (DCS) is an important option in the store of war surgery and surgery of trauma. The main purpose of our investigation was to specify the percentage of the injured who need DCS. We performed retrospective study of the patients in the combat operations in Chechnya (1994-2002) and in peacetime (2005-2010). Total lethality in group with the standard surgical approach was 62.3%. It was significantly higher than the lethality in group of patients who underwent DCS - 50.0% (p < 0.05). Thus, the experience of DCS in War Surgery Department confirms that DCS is perspective tendency in treatment of patients with severe and extremely severe trauma, and allows decreasing lethality in 12.3%.

Long-Term Outcomes of Patients with Lumbar Disc Herniation Treated with Percutaneous Discectomy: Comparative Study with Microendoscopic Discectomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Wengui; Wu Xiaotao; Guo Jinhe

We assessed the long-term outcomes of patients with lumbar disc herniation treated with percutaneous lumbar discectomy (PLD) or microendoscopic discectomy (MED). A retrospective study was performed in consecutive patients with lumbar disc herniation treated with PLD (n = 129) or MED (n = 101) in a single hospital from January 2000 to March 2002. All patients were followed up with MacNab criteria and self-evaluation questionnaires comprising the Oswestry Disability Index and Medical Outcomes Study 36-Item Short-Form Health Survey. Several statistical methods were used for analyses of the data, and a p value of <0.05 was considered to be statistically significant.more » A total of 104 patients (80.62%) with PLD and 82 patients (81.19%) with MED were eligible for analyses, with a mean follow-up period of 6.64 {+-} 0.67 years and 6.42 {+-} 0.51 years, respectively. There were no significant differences between the two groups in age, number of lesions, major symptoms and physical signs, and radiological findings. According to the MacNab criteria, 75.96% in the PLD group and 84.15% in the MED group achieved excellent or good results, respectively, this was statistically significant (p = 0.0402). With the Oswestry Disability Index questionnaires, the average scores and minimal disability, respectively, were 6.97 and 71.15% in the PLD group and 4.89 and 79.27% in the MED group. Total average scores of Medical Outcomes Study 36-Item Short-Form Health Survey were 75.88 vs. 81.86 in PLD group vs. MED group (p = 0.0582). The cost and length of hospitalization were higher or longer in MED group, a statistically significant difference (both p < 0.0001). Long-term complications were observed in two patients (2.44%) in the MED group, no such complications were observed in the PLD group. Both PLD and MED show an acceptable long-term efficacy for treatment of lumbar disc herniation. Compared with MED patients, long-term satisfaction is slightly lower in the PLD patients; complications, hospitalization duration, and costs in PLD group are also lower.« less

Immune mechanisms regulating pharmacokinetics and pharmacodynamics of PEGylated liposomal anticancer agents

NASA Astrophysics Data System (ADS)

Song, Gina

Nanotechnology has made significant advances in drug delivery system for the treatment of cancer. Among various nanoparticle (NP) platforms, liposomes have been most widely used as a NP drug carrier for cancer therapy. High variation in pharmacokinetics (PK) and pharmacodynamics (PD) of liposome-based therapeutics has been reported. However, the interaction of liposome-based therapeutics with the immune system, specifically the mononuclear phagocyte system (MPS), and underlying molecular mechanisms for variable responses to liposomal drugs remain poorly understood. The objective of this dissertation was to elucidate immune mechanisms for the variable responses to PEGylated liposomal doxorubicin (PLD; DoxilRTM), a clinically relevant NP, in animal models and in patients. In vitro, in vivo and clinical systems were investigated to evaluate the effects of chemokines (CCL2 and CCL5), heterogeneity of the tumor microenvironment, and genetic variations on PK and PD of PLD. Results showed that there was a significantly positive linear relationship between PLD exposure (AUC) and total amount of CCL2 and CCL5, most prevalent chemokines in plasma, in patients with recurrent ovarian cancer. Consistent with these findings, preclinical studies using mice bearing SKOV3 orthotopic ovarian cancer xenografts demonstrated that PLD induced the production and secretion of chemokines into plasma. In addition, in vitro studies using human monocytic THP-1 cells demonstrated that PLD altered monocyte migration towards CCL2 and CCL5. The PK and efficacy studies of PLD in murine models of breast cancer showed that heterogeneous tumor microenvironment was associated with significantly different tumor delivery and efficacy of PLD, but not small molecule doxorubicin between two breast tumor models. A candidate genetic locus that was associated with clearance of PLD in 23 inbred mouse strains contains a gene that encodes for engulfment adapter PTB domain containing 1 (Gulp1). By using integrated approaches, we were able to identify the immunological mechanisms at the molecular, tissue, and clinical levels that may contribute to inter-individual variability in PK and PD of PLD. This dissertation research has a potential to make an impact on development of future NP-based anticancer therapeutics as well as on clinical use of PLD (DoxilRTM) and other PEGylated liposomal anticancer agents.

Head-to-Head Visual Comparison between Brain Perfusion SPECT and Arterial Spin-Labeling MRI with Different Postlabeling Delays in Alzheimer Disease.

PubMed

Kaneta, T; Katsuse, O; Hirano, T; Ogawa, M; Yoshida, K; Odawara, T; Hirayasu, Y; Inoue, T

2017-08-01

Arterial spin-labeling MR imaging has been recently developed as a noninvasive technique with magnetically labeled arterial blood water as an endogenous contrast medium for the evaluation of CBF. Our aim was to compare arterial spin-labeling MR imaging and SPECT in the visual assessment of CBF in patients with Alzheimer disease. In 33 patients with Alzheimer disease or mild cognitive impairment due to Alzheimer disease, CBF images were obtained by using both arterial spin-labeling-MR imaging with a postlabeling delay of 1.5 seconds and 2.5 seconds (PLD 1.5 and PLD 2.5 , respectively) and brain perfusion SPECT. Twenty-two brain regions were visually assessed, and the diagnostic confidence of Alzheimer disease was recorded. Among all arterial spin-labeling images, 84.9% of PLD 1.5 and 9% of PLD 2.5 images showed the typical pattern of advanced Alzheimer disease (ie, decreased CBF in the bilateral parietal, temporal, and frontal lobes). PLD 1.5 , PLD 2.5 , and SPECT imaging resulted in obviously different visual assessments. PLD 1.5 showed a broad decrease in CBF, which could have been due to an early perfusion. In contrast, PLD 2.5 did not appear to be influenced by an early perfusion but showed fewer pathologic findings than SPECT. The distinctions observed by us should be carefully considered in the visual assessments of Alzheimer disease. Further studies are required to define the patterns of change in arterial spin-labeling-MR imaging associated with Alzheimer disease. © 2017 by American Journal of Neuroradiology.

Results of percutaneous sclerotherapy and surgical treatment in patients with symptomatic simple liver cysts and polycystic liver disease

PubMed Central

Erdogan, Deha; van Delden, Otto M; Rauws, Erik AJ; Busch, Olivier RC; Lameris, Johan S; Gouma, Dirk J; van Gulik, Thomas M

2007-01-01

AIM: To evaluate the results of the treatment of simple liver cysts (solitary and multiple) and polycystic liver disease (PLD) using percutaneous sclerotherapy and/or surgical procedures in a single tertiary referral centre. METHODS: Retrospective analysis of 54 patients referred for evaluation and possible treatment of simple liver cysts (solitary and multiple) and PLD, from January 1997 to July 2006. RESULTS: Simple liver cysts were treated in 41 pts (76%) with a mean size of 12.6 cm. The most common reason for referral was abdominal pain or discomfort (85%). Percutaneous sclerotherapy was performed as initial treatment in 30 pts, showing cyst recurrence in 6 pts (20%). Surgical treatment was initially performed in 11 pts with cyst recurrence in 3 pts (27%). PLD was treated in 13 pts (24%) with a mean size of the dominant cyst of 13 cm. Percutaneous sclerotherapy for PLD was performed in 9 pts with recurrence in 7 pts (77.8%). Surgical treatment for PLD was undertaken in 4 pts (30.8%) with recurrence in all. Eventually, 2 pts with PLD in the presence of polycystic kidney disease underwent liver- and kidney transplantation because of deterioration of liver and kidney function. CONCLUSION: The majority of patients with simple liver cysts and PLD are referred for progressive abdominal pain. As initial treatment, percutaneous sclerotherapy is appropriate. Surgical deroofing is indicated in case of cyst recurrence after percutaneous sclerotherapy. However, the results of percutaneous sclerotherapy and surgical treatment for PLD are disappointing. Partial liver resection is indicated when there is suspicion of a pre-malignant lesion. PMID:17589926

Phospholipase D and phosphatidic acid in plant defence response: from protein-protein and lipid-protein interactions to hormone signalling.

PubMed

Zhao, Jian

2015-04-01

Phospholipase Ds (PLDs) and PLD-derived phosphatidic acids (PAs) play vital roles in plant hormonal and environmental responses and various cellular dynamics. Recent studies have further expanded the functions of PLDs and PAs into plant-microbe interaction. The molecular diversities and redundant functions make PLD-PA an important signalling complex regulating lipid metabolism, cytoskeleton dynamics, vesicle trafficking, and hormonal signalling in plant defence through protein-protein and protein-lipid interactions or hormone signalling. Different PLD-PA signalling complexes and their targets have emerged as fast-growing research topics for understanding their numerous but not yet established roles in modifying pathogen perception, signal transduction, and downstream defence responses. Meanwhile, advanced lipidomics tools have allowed researchers to reveal further the mechanisms of PLD-PA signalling complexes in regulating lipid metabolism and signalling, and their impacts on jasmonic acid/oxylipins, salicylic acid, and other hormone signalling pathways that essentially mediate plant defence responses. This review attempts to summarize the progress made in spatial and temporal PLD/PA signalling as well as PLD/PA-mediated modification of plant defence. It presents an in-depth discussion on the functions and potential mechanisms of PLD-PA complexes in regulating actin filament/microtubule cytoskeleton, vesicle trafficking, and hormonal signalling, and in influencing lipid metabolism-derived metabolites as critical signalling components in plant defence responses. The discussion puts PLD-PA in a broader context in order to guide future research. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Probabilistic Model for Laser Damage to the Human Retina

DTIC Science & Technology

2012-03-01

the beam. Power density may be measured in radiant exposure, J cm2 , or by irradiance , W cm2 . In the experimental database used in this study and...to quan- tify a binary response, either lethal or non-lethal, within a population such as insects or rats. In directed energy research, probit...value of the normalized Arrhenius damage integral. In a one-dimensional simulation, the source term is determined as a spatially averaged irradiance (W

Cycling of the signaling protein phospholipase D through cilia requires the BBSome only for the export phase

PubMed Central

Brown, Jason M.; Sampaio, Julio L.; Craft, Julie M.; Shevchenko, Andrej; Evans, James E.; Witman, George B.

2013-01-01

The BBSome is a complex of seven proteins, including BBS4, that is cycled through cilia by intraflagellar transport (IFT). Previous work has shown that the membrane-associated signaling protein phospholipase D (PLD) accumulates abnormally in cilia of Chlamydomonas reinhardtii bbs mutants. Here we show that PLD is a component of wild-type cilia but is enriched ∼150-fold in bbs4 cilia; this accumulation occurs progressively over time and results in altered ciliary lipid composition. When wild-type BBSomes were introduced into bbs cells, PLD was rapidly removed from the mutant cilia, indicating the presence of an efficient BBSome-dependent mechanism for exporting ciliary PLD. This export requires retrograde IFT. Importantly, entry of PLD into cilia is BBSome and IFT independent. Therefore, the BBSome is required only for the export phase of a process that continuously cycles PLD through cilia. Another protein, carbonic anhydrase 6, is initially imported normally into bbs4 cilia but lost with time, suggesting that its loss is a secondary effect of BBSome deficiency. PMID:23589493

Effect of detergents, trypsin, and bivalent metal ions on interfacial activation and functioning of phospholipase D.

PubMed

Madyarov, Sh R

2014-07-01

The effects of detergents, trypsin, and bivalent metal ions on production of phosphatidic and lysophosphatidic acids by the action of phospholipase D (PLD) on lecithin and lysolecithin were studied. It was found that these reaction products and dodecyl sulfate ions activate PLD, whereas other anionic detergents are less effective. A protective effect of the functioning enzyme against its hydrolytic inactivation by trypsin was found. Bivalent metal ions can be arranged in the following sequence by their ability to activate PLD in the hydrolysis of lecithin and lysolecithin: Ca2+>Sr2+>Ba2+>Mg2+. These results are considered in relation to a proposed mechanism of activation and functioning of PLD with the participation of clusters of phosphatidates and lysophosphatidates. Such Me2+-induced formation of rafts or microdomains from the products of hydrolysis of phospholipids can rationalize not only PLD activation and self-regulation, but also the action of this mechanism on other components and properties of biomembranes. PLD and other lipolytic enzymes can be classified as lateral vector enzymes.

Localization of peroxisome proliferator-activated receptor alpha (PPARα) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD) in cells expressing the Ca2+-binding proteins calbindin, calretinin, and parvalbumin in the adult rat hippocampus

PubMed Central

Rivera, Patricia; Arrabal, Sergio; Vargas, Antonio; Blanco, Eduardo; Serrano, Antonia; Pavón, Francisco J.; Rodríguez de Fonseca, Fernando; Suárez, Juan

2014-01-01

The N-acylethanolamines (NAEs), oleoylethanolamide (OEA) and palmithylethanolamide (PEA) are known to be endogenous ligands of PPARα receptors, and their presence requires the activation of a specific phospholipase D (NAPE-PLD) associated with intracellular Ca2+ fluxes. Thus, the identification of a specific population of NAPE-PLD/PPARα-containing neurons that express selective Ca2+-binding proteins (CaBPs) may provide a neuroanatomical basis to better understand the PPARα system in the brain. For this purpose, we used double-label immunofluorescence and confocal laser scanning microscopy for the characterization of the co-existence of NAPE-PLD/PPARα and the CaBPs calbindin D28k, calretinin and parvalbumin in the rat hippocampus. PPARα expression was specifically localized in the cell nucleus and, occasionally, in the cytoplasm of the principal cells (dentate granular and CA pyramidal cells) and some non-principal cells of the hippocampus. PPARα was expressed in the calbindin-containing cells of the granular cell layer of the dentate gyrus (DG) and the SP of CA1. These principal PPARα+/calbindin+ cells were closely surrounded by NAPE-PLD+ fiber varicosities. No pyramidal PPARα+/calbindin+ cells were detected in CA3. Most cells containing parvalbumin expressed both NAPE-PLD and PPARα in the principal layers of the DG and CA1/3. A small number of cells containing PPARα and calretinin was found along the hippocampus. Scattered NAPE-PLD+/calretinin+ cells were specifically detected in CA3. NAPE-PLD+ puncta surrounded the calretinin+ cells localized in the principal cells of the DG and CA1. The identification of the hippocampal subpopulations of NAPE-PLD/PPARα-containing neurons that express selective CaBPs should be considered when analyzing the role of NAEs/PPARα-signaling system in the regulation of hippocampal functions. PMID:24672435

Localization of peroxisome proliferator-activated receptor alpha (PPARα) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD) in cells expressing the Ca(2+)-binding proteins calbindin, calretinin, and parvalbumin in the adult rat hippocampus.

PubMed

Rivera, Patricia; Arrabal, Sergio; Vargas, Antonio; Blanco, Eduardo; Serrano, Antonia; Pavón, Francisco J; Rodríguez de Fonseca, Fernando; Suárez, Juan

2014-01-01

The N-acylethanolamines (NAEs), oleoylethanolamide (OEA) and palmithylethanolamide (PEA) are known to be endogenous ligands of PPARα receptors, and their presence requires the activation of a specific phospholipase D (NAPE-PLD) associated with intracellular Ca(2+) fluxes. Thus, the identification of a specific population of NAPE-PLD/PPARα-containing neurons that express selective Ca(2+)-binding proteins (CaBPs) may provide a neuroanatomical basis to better understand the PPARα system in the brain. For this purpose, we used double-label immunofluorescence and confocal laser scanning microscopy for the characterization of the co-existence of NAPE-PLD/PPARα and the CaBPs calbindin D28k, calretinin and parvalbumin in the rat hippocampus. PPARα expression was specifically localized in the cell nucleus and, occasionally, in the cytoplasm of the principal cells (dentate granular and CA pyramidal cells) and some non-principal cells of the hippocampus. PPARα was expressed in the calbindin-containing cells of the granular cell layer of the dentate gyrus (DG) and the SP of CA1. These principal PPARα(+)/calbindin(+) cells were closely surrounded by NAPE-PLD(+) fiber varicosities. No pyramidal PPARα(+)/calbindin(+) cells were detected in CA3. Most cells containing parvalbumin expressed both NAPE-PLD and PPARα in the principal layers of the DG and CA1/3. A small number of cells containing PPARα and calretinin was found along the hippocampus. Scattered NAPE-PLD(+)/calretinin(+) cells were specifically detected in CA3. NAPE-PLD(+) puncta surrounded the calretinin(+) cells localized in the principal cells of the DG and CA1. The identification of the hippocampal subpopulations of NAPE-PLD/PPARα-containing neurons that express selective CaBPs should be considered when analyzing the role of NAEs/PPARα-signaling system in the regulation of hippocampal functions.

Isolation and characterization of a 66-kDa protein from rat liver plasma membrane with RhoA-stimulated phospholipase D activity.

PubMed

Dunkirk, Shawn G; Wallert, Mark A; Baumgartner, Matt L; Provost, Joseph J

2002-02-01

A 66-kDa molecular weight protein with phospholipase D activity was solubilized and partially purified from rat liver plasma membrane. The activity and regulation of this phospholipase D have been characterized. Immunoblot analyses indicated that the enzyme was distinct from hPLD1 and PLD2, but was recognized by an antibody to the 12 terminal amino acids of PLD1. PLD activity was stimulated by 1-100 microM Ca(2+) and Mg(2+) and displayed a pH optimum of 7.5. Activity was inhibited by both saturated and unsaturated fatty acids. This PLD was activated in an ATP-independent manner by the PKC isozymes alpha and betaII but not activated by other PKC isozymes. It was also stimulated by the small G-proteins RhoA and ARF. RhoA stimulated the greatest activation, followed by ARF and PKC(alpha). This enzyme was further activated in a synergistic manner when combinations of PKC(alpha) and RhoA or ARF were used. This enzyme displayed a greater response activation by RhoA than to activation by ARF. While a potential breakdown product of PLD1, activation by RhoA indicates that the PLD characterized here is distinct from the other PLDs cloned or isolated to date. Copyright 2002 Elsevier Science (USA).

Identification and characterization of phospholipase D and its association with drought susceptibilities in peanut (Arachis hypogaea).

PubMed

Guo, B Z; Xu, G; Cao, Y G; Holbrook, C C; Lynch, R E

2006-02-01

Preharvest aflatoxin contamination has been identified by the peanut industry as a serious issue in food safety and human health because of the carcinogenic toxicity. Drought stress is the most important environmental factor exacerbating Aspergillus infection and aflatoxin contamination in peanut. The development of drought-tolerant peanut cultivars could reduce aflatoxin contamination and would represent a major advance in the peanut industry. In this study, we identified a novel PLD gene in peanut (Arachis hypogaea), encoding a putative phospholipase D (PLD, EC 3.1.4.4). The completed cDNA sequence was obtained by using the consensus-degenerated hybrid oligonucleotide primer strategy. The deduced amino acid sequence shows high identity with known PLDs, and has similar conserved domains. The PLD gene expression under drought stress has been studied using four peanut lines: Tifton 8 and A13 (both drought tolerant) and Georgia Green (moderate) and PI 196754 (drought sensitive). Northern analysis showed that PLD gene expression was induced faster by drought stress in the drought-sensitive lines than the drought tolerance lines. Southern analysis showed that cultivated peanut has multiple copies (3 to 5 copies) of the PLD gene. These results suggest that peanut PLD may be involved in drought sensitivity and tolerance responses. Peanut PLD gene expression may be useful as a tool in germplasm screening for drought tolerance.

Plasma glycosylphosphatidylinositol-specific phospholipase D predicts the change in insulin sensitivity in response to a low-fat but not a low-carbohydrate diet in obese women.

PubMed

Gray, Dona L; O'Brien, Kevin D; D'Alessio, David A; Brehm, Bonnie J; Deeg, Mark A

2008-04-01

Although circulating glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD), a minor high-density lipoprotein-associated protein, is elevated in patients with insulin resistance or high triglycerides, no information is available on the effect of weight loss or changes in insulin sensitivity on circulating GPI-PLD levels. The objective of the study was to determine the effect of weight loss and changes in insulin sensitivity on plasma GPI-PLD levels. Forty-two nondiabetic obese women were included in the study, which involved a 3-month dietary intervention randomizing patients to a low-fat or a low-carbohydrate diet. The study's main outcome measures were plasma GPI-PLD levels and insulin sensitivity as estimated by the homeostasis model assessment. The very low carbohydrate diet group lost more weight after 3 months (-7.6 +/- 3.2 vs -4.2 +/- 3.5 kg, P < .01), although the decrease in insulin resistance was similar between groups. Weight loss with either diet did not alter plasma GPI-PLD levels. However, baseline GPI-PLD levels correlated with the change in insulin sensitivity in response to the low-fat diet, whereas baseline insulin sensitivity correlated with the change in insulin sensitivity in response to the low-carbohydrate diet. Plasma GPI-PLD may serve as a clinical tool to determine the effect of a low-fat diet on insulin sensitivity.

Hepatic Phospholipidosis Is Associated with Altered Hepatobiliary Function as Assessed by Gadoxetate Dynamic Contrast-enhanced Magnetic Resonance Imaging.

PubMed

Lenhard, Stephen C; Lev, Mally; Webster, Lindsey O; Peterson, Richard A; Goulbourne, Christopher N; Miller, Richard T; Jucker, Beat M

2016-01-01

To determine if amiodarone induces hepatic phospholipidosis (PLD) sufficient to detect changes in hepatobiliary transporter function as assessed by gadoxetate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), rats were orally dosed with vehicle (1% methyl cellulose) or amiodarone (300 mg/kg/day) for 7 consecutive days. Gadoxetate DCE-MRI occurred at baseline, day 7, and following a 2-week washout of amiodarone. At day 7, the gadoxetate washout rate was significantly decreased compared to the vehicle group. Blood chemistry analysis revealed no significant changes in liver enzymes (alanine aminotransferase [ALT]/aspartate aminotransferase [AST]/alkaline phosphatase [ALP]), bilirubin, or bile acids between vehicle or amiodarone groups. Hepatic PLD was confirmed in all rats treated with amiodarone at day 7 by transmission electron microscopy. Following the 2-week washout, there was no ultrastructural evidence of hepatic PLD in rats and the gadoxetate washout rate returned to baseline levels. This is the first study to show the application of gadoxetate DCE-MRI to detect hepatobiliary functional changes associated with PLD and offer a potential new technique with clinical utility in patients suspected of having PLD. These results also suggest PLD itself has functional consequences on hepatobiliary function in the absence of biomarkers of toxicity, given the cause/effect relationship between PLD and function has not been fully established. © The Author(s) 2015.

Cholinergic dysfunctions and enhanced oxidative stress in the neurobehavioral toxicity of lambda-cyhalothrin in developing rats.

PubMed

Ansari, Reyaz W; Shukla, Rajendra K; Yadav, Rajesh S; Seth, Kavita; Pant, Aditya B; Singh, Dhirendra; Agrawal, Ashok K; Islam, Fakhrul; Khanna, Vinay K

2012-11-01

This study is focused on understanding the mechanism of neurobehavioral toxicity of lambda-cyhalothrin, a new generation type II synthetic pyrethroid in developing rats following their exposure from post-lactational day (PLD)22 to PLD49 and investigate whether neurobehavioral alterations are transient or persistent. Post-lactational exposure to lambda-cyhalothrin (1.0 or 3.0 mg/kg body weight, p.o.) affected grip strength and learning activity in rats on PLD50 and the persistent impairment of grip strength and learning was observed at 15 days after withdrawal of exposure on PLD65. A decrease in the binding of muscarinic-cholinergic receptors in frontocortical, hippocampal, and cerebellar membranes associated with decreased expression of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) in hippocampus was observed following exposure to lambda-cyhalothrin on PLD50 and PLD65. Exposure to lambda-cyhalothrin was also found to increase the expression of growth-associated protein-43 in hippocampus of rats on PLD50 and PLD65 as compared to controls. A significant increase in lipid peroxidation and protein carbonyl levels and decreased levels of reduced glutathione and activity of superoxide dismutase, catalase, and glutathione peroxidase in brain regions of lambda-cyhalothrin exposed rats were distinctly observed indicating increased oxidative stress. Inhibition of ChAT and AChE activity may cause down-regulation of muscarinic-cholinergic receptors consequently impairing learning activity in developing rats exposed to lambda-cyhalothrin. The data further indicate that long-term exposure to lambda-cyhalothrin at low doses may be detrimental and changes in selected behavioral and neurochemical end points may persist if exposure to lambda-cyhalothrin continues.

Requirement of GM2 ganglioside activator for phospholipase D activation

PubMed Central

Nakamura, Shun-ichi; Akisue, Toshihiro; Jinnai, Hitoshi; Hitomi, Tomohiro; Sarkar, Sukumar; Miwa, Noriko; Okada, Taro; Yoshida, Kimihisa; Kuroda, Shun’ichi; Kikkawa, Ushio; Nishizuka, Yasutomi

1998-01-01

Sequence analysis of a heat-stable protein necessary for the activation of ADP ribosylation factor-dependent phospholipase D (PLD) reveals that this protein has a structure highly homologous to the previously known GM2 ganglioside activator whose deficiency results in the AB-variant of GM2 gangliosidosis. The heat-stable activator protein indeed has the capacity to enhance enzymatic conversion of GM2 to GM3 ganglioside that is catalyzed by β-hexosaminidase A. Inversely, GM2 ganglioside activator purified separately from tissues as described earlier [Conzelmann, E. & Sandhoff, K. (1987) Methods Enzymol. 138, 792–815] stimulates ADP ribosylation factor-dependent PLD in a dose-dependent manner. At higher concentrations of ammonium sulfate, the PLD activator protein apparently substitutes for protein kinase C and phosphatidylinositol 4,5-bisphosphate, both of which are known as effective stimulators of the PLD reaction. The mechanism of action of the heat-stable PLD activator protein remains unknown. PMID:9770472

Imbibitional damage in conidia of the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Metarhizium acridum

USDA-ARS?s Scientific Manuscript database

When dried organisms are immersed in water, rapid imbibition may cause severe damage to plasma membranes; in unicellular organisms, such damage is usually lethal. This study investigated effects of pre-immersion moisture levels and immersion temperature on imbibitional damage in three insect pathoge...

A Comparison of MOCLD With PLD Ba(x)Sr(1-x)TiO3 Thin Films on LaAlO3 for Tunable Microwave Applications

NASA Technical Reports Server (NTRS)

VanKeuls, F. W.; Mueller, C. H.; Romanofsky, R. R.; Warner, J. D.; Miranda, F. A.; Jiang, H.

2002-01-01

Historically, tunable dielectric devices using thin crystalline Ba(x)Sr(1-x)TiO3 (BST) films deposited on lattice-matched substrates, such as LaAlO3, have generally been grown using pulsed laser deposition (PLD). Highly oriented BST films can be grown by PLD but large projects are hampered by constraints of deposition area, deposition time and expense. The Metal-Organic Chemical Liquid Deposition (MOCLD) process allows for larger areas, faster turnover and lower cost. Several BST films deposited on LaAlO3 by MOCLD have been tested in 16 GHz coupled microstrip phase shifters. They can be compared with many PLD BST films tested in the same circuit design. The MOCLD phase shifter performance of 293 deg. phase shift with 53 V/micron dc bias and a figure of merit of 47 deg./dB is comparable to the most highly oriented PLD BST films. The PLD BST films used here have measured XRD full-width-at-half-maxima (FWHM) as low as 0.047 deg.. The best FWHM of these MOCLD BST films has been measured to be 0.058 deg.

Binding of PLD2-Generated Phosphatidic Acid to KIF5B Promotes MT1-MMP Surface Trafficking and Lung Metastasis of Mouse Breast Cancer Cells.

PubMed

Wang, Ziqing; Zhang, Feng; He, Jingquan; Wu, Ping; Tay, Li Wei Rachel; Cai, Ming; Nian, Weiqi; Weng, Yuanyuan; Qin, Li; Chang, Jeffrey T; McIntire, Laura B; Di Paolo, Gilbert; Xu, Jianming; Peng, Junmin; Du, Guangwei

2017-10-23

Little is known about the cellular events promoting metastasis. We show that knockout of phospholipase D 2 (PLD2), which generates the signaling lipid phosphatidic acid (PA), inhibits lung metastases in the mammary tumor virus (MMTV)-Neu transgenic mouse breast cancer model. PLD2 promotes local invasion through the regulation of the plasma membrane targeting of MT1-MMP and its associated invadopodia. A liposome pull-down screen identifies KIF5B, the heavy chain of the motor protein kinesin-1, as a new PA-binding protein. In vitro assays reveal that PA specifically and directly binds to the C terminus of KIF5B. The binding between PLD2-generated PA and KIF5B is required for the vesicular association of KIF5B, surface localization of MT1-MMP, invadopodia, and invasion in cancer cells. Taken together, these results identify a role of PLD2-generated PA in the regulation of kinesin-1 motor functions and breast cancer metastasis and suggest PLD2 as a potential therapeutic target for metastatic breast cancer. Copyright © 2017 Elsevier Inc. All rights reserved.

Efficient Extracellular Expression of Phospholipase D in Escherichia Coli with an Optimized Signal Peptide

NASA Astrophysics Data System (ADS)

Yang, Leyun; Xu, Yu; Chen, Yong; Ying, Hanjie

2018-01-01

New secretion vectors containing the synthetic signal sequence (OmpA’) was constructed for the secretory production of recombinant proteins in Escherichia coli. The E. coli Phospholipase D structural gene (Accession number:NC_018658) fused to various signal sequence were expressed from the Lac promoter in E. coli Rosetta strains by induction with 0.4mM IPTG at 28°C for 48h. SDS-PaGe analysis of expression and subcellular fractions of recombinant constructs revealed the translocation of Phospholipase D (PLD) not only to the medium but also remained in periplasm of E. coli with OmpA’ signal sequence at the N-terminus of PLD. Thus the study on the effects of various surfactants on PLD extracellular production in Escherichia coli in shake flasks revealed that optimal PLD extracellular production could be achieved by adding 0.4% Triton X-100 into the medium. The maximal extracellular PLD production and extracellular enzyme activity were 0.23mg ml-1 and 16U ml-1, respectively. These results demonstrate the possibility of efficient secretory production of recombinant PLD in E. coli should be a potential industrial applications.

25 years of pulsed laser deposition

NASA Astrophysics Data System (ADS)

Lorenz, Michael; Ramachandra Rao, M. S.

2014-01-01

It is our pleasure to introduce this special issue appearing on the occasion of the 25th anniversary of pulsed laser deposition (PLD), which is today one of the most versatile growth techniques for oxide thin films and nanostructures. Ever since its invention, PLD has revolutionized the research on advanced functional oxides due to its ability to yield high-quality thin films, multilayers and heterostructures of a variety of multi-element material systems with rather simple technical means. We appreciate that the use of lasers to deposit films via ablation (now termed PLD) has been known since the 1960s after the invention of the first ruby laser. However, in the first two decades, PLD was something of a 'sleeping beauty' with only a few publications per year, as shown below. This state of hibernation ended abruptly with the advent of high T c superconductor research when scientists needed to grow high-quality thin films of multi-component high T c oxide systems. When most of the conventional growth techniques failed, the invention of PLD by T (Venky) Venkatesan clearly demonstrated that the newly discovered high-T c superconductor, YBa2Cu3O7-δ , could be stoichiometrically deposited as a high-quality nm-thin film with PLD [1]. As a remarkable highlight of this special issue, Venkatesan gives us his very personal reminiscence on these particularly innovative years of PLD beginning in 1986 [2]. After Venky's first paper [1], the importance of this invention was realized worldwide and the number of publications on PLD increased exponentially, as shown in figure 1. Figure 1. Figure 1. Published items per year with title or topic PLD. Data from Thomson Reuters Web of Knowledge in September 2013. After publication of Venky's famous paper in 1987 [1], the story of PLD's success began with a sudden jump in the number of publications, about 25 years ago. A first PLD textbook covering its basic understanding was soon published, in 1994, by Chrisey and Hubler [3]. Within a decade, large-area PLD grown YBa2Cu3O7-δ thin films became a reality for applications in microwave filters for satellite and mobile communication. The material systems that could be covered under the PLD gamut extended to almost all oxides, nitrides and even organics. A second textbook exclusively dedicated to PLD was edited by Rob Eason in 2007 [4], reviewing many possible modifications and extensions of the method. To celebrate 25 years of pulsed laser deposition, Venkatesan organized a symposium on 'Recent Advances in the Pulsed Laser Deposition of Thin Films and Nanostructures' in 2013 [5]. Besides dielectric, ferroelectric and magnetic oxides, the wide-bandgap group II-VI semiconductor ZnO is among the most intensively researched compounds during the last decade. Therefore, this material has become the subject of two introductory reviews in this issue by Opel et al and Tsukazaki et al , to show the state-of-the-art work carried out on ZnO thin films to 2013. The detailed insights into growth parameter control and their impact on the ZnO film performance make both reviews highly instructional not only for specialists, but also for beginners in PLD. The perspective of PLD towards industrial applications largely depends, first, on the ability of the excimer laser suppliers to further increase the laser power and, second, on the deposition schemes to distribute the ablated material homogeneously on technologically relevant substrate areas (8-inch diameter). These developments are explained here by the leading companies dealing with high-power excimer lasers and large-area PLD equipment, such as Coherent Laser Systems GmbH, PVD Products, Inc., and SolMateS B.V. It is also important to note the efforts made by Blank and Rijnders for atomic layer control of PLD by in situ high-pressure reflection high-energy electron diffraction (RHEED), which is now adopted by many groups worldwide. The potential of multi-beam PLD for advanced optical waveguides and of advanced design-of-experiment schemes to shorten the optimization effort for new materials is presented at the end of this methodical section. Further, the issue contains original papers on other prominent PLD activities, such as dielectric SrTiO3 films, magnetic and spintronic La1-x Srx MnO3, and multiferroic BiFeO3. The role of cationic and anionic point defects and their control during PLD is discussed based on the examples of the simple perovskite SrMoO3 and the double perovskite Sr2CrWO6. The final paper in this thin-film-related section provides a good account of in situ high-temperature surface smoothing of Ba2TiSi2O8 fresnoite films and growth from glassy fresnoite targets with 100% theoretical density. The flexibility of the PLD technique has resulted in several schemes to grow nanostructures, which is unique in the nature of PLD. Okada's group succeeded in controlling the growth density of ZnO nanowires by varying the thickness of the ZnO buffer layer, and nanowalls could be patterned by interference phenomenon using laser irradiation. PLD-based methods are further used to grow metal nanoparticle plasmonic films with packing densities up to 1011 particles cm-2, and ZnO nanowires from screw dislocation driven two-dimensional hexagonal stacking on diamond substrates. Overall, this special issue provides an up-to-date overview on the current status, potential and the extraordinary success and development of PLD from a simple laboratory growth method to a viable industrial technique for fabrication of advanced oxide thin films. We thank all the authors and reviewers for their contributions to this special issue. We would like to place on record our gratitude for the timely help extended by the editorial team, Dr Olivia Roche, Dean Williams and Colin Adcock. References [1] Dijkkamp D, Venkatesan T, Wu X D, Shaheen S A, Jisrawi N, Min-Lee Y-H, McLean W L and Croft M 1987 Preparation of YBaCu oxide superconductor thin films using pulsed laser evaporation from high T c bulk material Appl. Phys. Lett. 51 619 [2] Venkatesan T 2014 Pulsed laser deposition—invention or discovery? J. Phys. D: Appl. Phys. 46 034001 [3] D B Chrisey, G H Hubler, 1994 Pulsed Laser Deposition of Thin Films (New York: Wiley) [4] R Eason, 2007 Pulsed Laser Deposition of Thin Films—Applications-Led Growth of Functional Materials (Hoboken, NJ: Wiley-Interscience) [5] MRS Singapore ICMAT Symposia Proceedings, Procedia Engineering (2013) Symposium IRecent Advances in the Pulsed Laser Deposition of Thin Films and Nanostructures at press

The molecular basis of leukocyte adhesion involving phosphatidic acid and phospholipase D.

PubMed

Speranza, Francis; Mahankali, Madhu; Henkels, Karen M; Gomez-Cambronero, Julian

2014-10-17

Defining how leukocytes adhere to solid surfaces, such as capillary beds, and the subsequent migration through the extracellular matrix, is a central biological issue. We show here that phospholipase D (PLD) and its enzymatic reaction product, phosphatidic acid (PA), regulate cell adhesion of immune cells (macrophages and neutrophils) to collagen and have defined the underlying molecular mechanism in a spatio-temporal manner that coincides with PLD activity timing. A rapid (t½ = 4 min) and transient activation of the PLD1 isoform occurs upon adhesion, and a slower (t½ = 7.5 min) but prolonged (>30 min) activation occurs for PLD2. Importantly, PA directly binds to actin-related protein 3 (Arp3) at EC50 = 22 nm, whereas control phosphatidylcholine did not bind. PA-activated Arp3 hastens actin nucleation with a kinetics of t½ = 3 min at 300 nm (compared with controls of no PA, t½ = 5 min). Thus, PLD and PA are intrinsic components of cell adhesion, which reinforce each other in a positive feedback loop and react from cues from their respective solid substrates. In nascent adhesion, PLD1 is key, whereas a sustained adhesion in mature or established focal points is dependent upon PLD2, PA, and Arp3. A prolonged adhesion could effectively counteract the reversible intrinsic nature of this cellular process and constitute a key player in chronic inflammation. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

[Procedural learning disorder: neuropsychological characteristics].

PubMed

Crespo-Eguílaz, N; Narbona, J

This research aims at neurocognitive delineation of the core features of procedural learning disorder (PLD), otherwise labeled as motor coordination disorder or non-verbal learning disorder. A sample of 209 correlative outpatients (73% males), aged 6-12 years, all of them having QI ranging from 81 to 120, was clustered into the following neurobehavioural groups: PLD (n = 16), PLD plus attention deficit hyperactivity disorder (ADHD) (n = 37), ADHD combined type (n = 47), ADHD predominantly inattentive type (n = 23), specific language impairment (n = 68), and semantic-pragmatic language impairment (n = 18). Two additional groups of patients were included for some comparisons: children with periventricular leukomalacia (PVL) without learning disability (n = 8) or associating PLD (n = 17). A set of behavioural scales and neurocognitive tests was used to evaluate verbal and non-verbal IQ, attention, impulsivity control, visuo-motor coordination, declarative memory, procedural memory and learning, formal and functional dimensions of language, peer relationships and academic achievement. Parametric analysis were used to test the differences and similarities of neurobehavioural variables between groups. Our results allow us to conclude that PLD implies a difficult acquisition of automatized motor, cognitive and communicative abilities required in school work and peer social relationships. PLD is different from autistic spectrum disorders. It is frequently associated to inattentive ADHD. Operational criteria for diagnosis of PLD are proposed, according to our results. A bilateral posterior parietal dysfunction is a plausible explanation of its physiopathology. Preserved general intelligence and formal linguistic abilities are the clues for intervention designs.

Investigation of Hexadecylphosphocholine (miltefosine) usage in Pegylated liposomal doxorubicin as a synergistic ingredient: In vitro and in vivo evaluation in mice bearing C26 colon carcinoma and B16F0 melanoma.

PubMed

Teymouri, Manouchehr; Farzaneh, Hamidreza; Badiee, Ali; Golmohammadzadeh, Shiva; Sadri, Kayvan; Jaafari, Mahmoud Reza

2015-12-01

In this investigation, Hexadecylphosphocholine (HePC, miltefosine) was being used as a new ingredient in Pegylated liposomal doxorubicin (PLD) and different aspects of this integration such as its effect on doxorubicin (Dox) release and cell uptake, cytotoxicity of liposomes, in vivo distribution and half-life clearance time of Dox as well as median survival time were illustrated. The liposomal formulations were Pegylated liposomal doxorubicin containing 0, 0.5, 1, 2 and 4% mole ratios of HePC (HePC-PLD) and their respective Dox-free liposomes (HePC-PLs). The cells used were colon carcinoma (C26), adriamycin-resistant breast cancer (MCF-7-ADR), and B16F0 melanoma cell lines, of which C26 and B16F0 cells were exploited for tumoring in BALB/c and C57Bl/6 mice, respectively. In most cases, increase in miltefosine percentage resulted in physically liposomal instability, increased Dox delivery and toxicity and reduced blood half-life of Dox. Overall, HePC 4% -PLD and PLD differed significantly in many respects and it was considered too toxic to be injected at the same dose (15mg Dox/ kg) as PLD. Although HePC 2% -PLD could extend the median survival time marginally in comparison to PLD, the concept of HePC- containing liposomes merits further investigation. Copyright © 2015 Elsevier B.V. All rights reserved.

Sub-Lethal Dose of Shiga Toxin 2 from Enterohemorrhagic Escherichia coli Affects Balance and Cerebellar Cytoarchitecture

PubMed Central

Pinto, Alipio; Cangelosi, Adriana; Geoghegan, Patricia A.; Tironi-Farinati, Carla; Brener, Gabriela J.; Goldstein, Jorge

2016-01-01

Shiga toxin producing Escherichia coli may damage the central nervous system before or concomitantly to manifested hemolytic–uremic syndrome symptoms. The cerebellum is frequently damaged during this syndrome, however, the deleterious effects of Shiga toxin 2 has never been integrally reported by ultrastructural, physiological and behavioral means. The aim of this study was to determine the cerebellar compromise after intravenous administration of a sub-lethal dose of Shiga toxin 2 by measuring the cerebellar blood–brain barrier permeability, behavioral task of cerebellar functionality (inclined plane test), and ultrastructural analysis (transmission electron microscope). Intravenous administration of vehicle (control group), sub-lethal dose of 0.5 and 1 ηg of Stx2 per mouse were tested for behavioral and ultrastructural studies. A set of three independent experiments were performed for each study (n = 6). Blood–brain barrier resulted damaged and consequently its permeability was significantly increased. Lower scores obtained in the inclined plane task denoted poor cerebellar functionality in comparison to their controls. The most significant lower score was obtained after 5 days of 1 ηg of toxin administration. Transmission electron microscope micrographs from the Stx2-treated groups showed neurons with a progressive neurodegenerative condition in a dose dependent manner. As sub-lethal intravenous Shiga toxin 2 altered the blood brain barrier permeability in the cerebellum the toxin penetrated the cerebellar parenchyma and produced cell damaged with significant functional implications in the test balance. PMID:26904009

Contemporary Practice in Professional Learning and Development of Early Childhood Educators in Australia: Reflections on What Works and Why

ERIC Educational Resources Information Center

Hadley, Fay; Waniganayake, Manjula; Shepherd, Wendy

2015-01-01

Continuous professional learning and development (PLD) is an essential component of effective practice in any profession. PLD as a professional responsibility and workplace requirement in early childhood (EC) settings is now embedded in Australian national policy. What PLD looks like and how it happens in EC settings is a hot topic both locally…

Delays in Prior Living Kidney Donors Receiving Priority on the Transplant Waiting List

PubMed Central

Klassen, David K.; Kucheryavaya, Anna Y.; Stewart, Darren E.

2016-01-01

Background and objectives Prior living donors (PLDs) receive very high priority on the Organ Procurement and Transplantation Network (OPTN) kidney waiting list. Program delays in adding PLDs to the waiting list, setting their status to active, and submitting requests for PLD priority can affect timely access to transplantation. Design, setting, participants, & measurements We used the OPTN and the Centers for Medicare and Medicaid Services data to examine timing of (1) listing relative to start of dialysis, (2) activation on the waiting list, and (3) requests for PLD priority relative to listing date. There were 210 PLDs (221 registrations) added to the OPTN kidney waiting list between January 1, 2010 and July 31, 2015. Results As of September 4, 2015, 167 of the 210 PLDs received deceased donor transplants, six received living donor transplants, two died, five were too sick to transplant, and 29 were still waiting. Median waiting time to deceased donor transplant for PLDs was 98 days. Only 40.7% of 221 PLD registrations (n=90) were listed before they began dialysis; 68.3% were in inactive status for <90 days, 17.6% were in inactive status for 90–365 days, 8.6% were in inactive status for 1–2 years, and 5.4% were in inactive status for >2 years. Median time of PLDs waiting in active status before receiving PLD priority was 2 days (range =0–1450); 67.4% of PLDs received PLD priority within 7 days after activation, but 15.4% waited 8–30 days, 8.1% waited 1–3 months, 4.1% waited 3–12 months, and 5.0% waited >1 year in active status for PLD priority. After receiving priority, most were transplanted quickly. Median time in active status with PLD priority before deceased donor transplant was 23 days. Conclusions Fewer than one half of listed PLDs were listed before starting dialysis. Most listed PLDs are immediately set to active status and receive PLD priority quickly, but a substantial number spends time in active status without PLD priority or a large amount of time in inactive status, which affects access to timely transplants. PMID:27591296

A Synthetic Lethal Screen Identifies DNA Repair Pathways that Sensitize Cancer Cells to Combined ATR Inhibition and Cisplatin Treatments

PubMed Central

Mohni, Kareem N.; Thompson, Petria S.; Luzwick, Jessica W.; Glick, Gloria G.; Pendleton, Christopher S.; Lehmann, Brian D.; Pietenpol, Jennifer A.; Cortez, David

2015-01-01

The DNA damage response kinase ATR may be a useful cancer therapeutic target. ATR inhibition synergizes with loss of ERCC1, ATM, XRCC1 and DNA damaging chemotherapy agents. Clinical trials have begun using ATR inhibitors in combination with cisplatin. Here we report the first synthetic lethality screen with a combination treatment of an ATR inhibitor (ATRi) and cisplatin. Combination treatment with ATRi/cisplatin is synthetically lethal with loss of the TLS polymerase ζ and 53BP1. Other DNA repair pathways including homologous recombination and mismatch repair do not exhibit synthetic lethal interactions with ATRi/cisplatin, even though loss of some of these repair pathways sensitizes cells to cisplatin as a single-agent. We also report that ATRi strongly synergizes with PARP inhibition, even in homologous recombination-proficient backgrounds. Lastly, ATR inhibitors were able to resensitize cisplatin-resistant cell lines to cisplatin. These data provide a comprehensive analysis of DNA repair pathways that exhibit synthetic lethality with ATR inhibitors when combined with cisplatin chemotherapy, and will help guide patient selection strategies as ATR inhibitors progress into the cancer clinic. PMID:25965342

Mammalian phospholipase D: activation by ammonium sulfate and nucleotides.

PubMed Central

Nakamura, S; Shimooku, K; Akisue, T; Jinnai, H; Hitomi, T; Kiyohara, Y; Ogino, C; Yoshida, K; Nishizuka, Y

1995-01-01

Phospholipase D (PLD) associated with the rat kidney membrane was activated by guanine 5'-[gamma-thio]triphosphate and a cytosol fraction that contained ADP-ribosylation factor. When assayed by measuring the phosphatidyl transfer reaction to ethanol with exogenously added radioactive phosphatidylcholine as substrate, the PLD required a high concentration (1.6 M) of ammonium sulfate to exhibit high enzymatic activity. Other salts examined were far less effective or practically inactive, and this dramatic action of ammonium sulfate is not simply due to such high ionic strength. Addition of ATP but not of nonhydrolyzable ATP analogue adenosine 5'-[beta, gamma-imido]diphosphate further enhanced the PLD activation approximately equal to 2- to 3-fold. This enhancement by ATP needed cytosol, implying a role of protein phosphorylation. A survey of PLD activity in rat tissues revealed that, unlike in previous observations reported thus far, PLD was most abundant in membrane fractions of kidney, spleen, and liver in this order, and the enzymatic activity in brain and lung was low. PMID:8618893

Adipose tissue NAPE-PLD controls fat mass development by altering the browning process and gut microbiota

PubMed Central

Geurts, Lucie; Everard, Amandine; Van Hul, Matthias; Essaghir, Ahmed; Duparc, Thibaut; Matamoros, Sébastien; Plovier, Hubert; Castel, Julien; Denis, Raphael G. P.; Bergiers, Marie; Druart, Céline; Alhouayek, Mireille; Delzenne, Nathalie M.; Muccioli, Giulio G.; Demoulin, Jean-Baptiste; Luquet, Serge; Cani, Patrice D.

2015-01-01

Obesity is a pandemic disease associated with many metabolic alterations and involves several organs and systems. The endocannabinoid system (ECS) appears to be a key regulator of energy homeostasis and metabolism. Here we show that specific deletion of the ECS synthesizing enzyme, NAPE-PLD, in adipocytes induces obesity, glucose intolerance, adipose tissue inflammation and altered lipid metabolism. We report that Napepld-deleted mice present an altered browning programme and are less responsive to cold-induced browning, highlighting the essential role of NAPE-PLD in regulating energy homeostasis and metabolism in the physiological state. Our results indicate that these alterations are mediated by a shift in gut microbiota composition that can partially transfer the phenotype to germ-free mice. Together, our findings uncover a role of adipose tissue NAPE-PLD on whole-body metabolism and provide support for targeting NAPE-PLD-derived bioactive lipids to treat obesity and related metabolic disorders. PMID:25757720

RhoA mediates the expression of acidic extracellular pH-induced matrix metalloproteinase-9 mRNA through phospholipase D1 in mouse metastatic B16-BL6 melanoma cells.

PubMed

Maeda, Toyonobu; Yuzawa, Satoshi; Suzuki, Atsuko; Baba, Yuh; Nishimura, Yukio; Kato, Yasumasa

2016-03-01

Solid tumors are characterized by acidic extracellular pH (pHe). The present study examined the contribution of small GTP-binding proteins to phospholipase D (PLD) activation of acidic pHe-induced matrix metalloproteinase-9 (MMP-9) production. Acidic pHe-induced MMP-9 production was reduced by C3 exoenzyme, which inhibits the Rho family of GTPases; cytochalasin D, which inhibits actin reorganization; and simvastatin, which inhibits geranylgeranylation of Rho. Small interfering RNA (siRNA) against RhoA, but not against Rac1 or Cdc42, significantly inhibited acidic pHe induction of MMP-9. Pull-down assays showed that acidic pHe increased the activated form of RhoA. Forced expression of constitutively active RhoA induced MMP-9 production, even at neutral pHe. RhoA siRNA also reduced acidic pHe induced PLD activity. Specific inhibition of PLD1 and Pld1 gene knockout significantly reduced acidic pHe-induced MMP-9 expression. In contrast, PLD2 inhibition or knockout had no effect on MMP-9 expression. These findings suggested that RhoA-PLD1 signaling is involved in acidic pHe induction of MMP-9.

Noise exposure estimates of urban MP3 player users.

PubMed

Levey, Sandra; Levey, Tania; Fligor, Brian J

2011-02-01

To examine the sound level and duration of use of personal listening devices (PLDs) by 189 college students, ages 18-53 years, as they entered a New York City college campus, to determine whether noise exposure from PLDs was in excess of recommended exposure limits and what factors might influence exposure. Free-field equivalent sound levels from PLD headphones were measured on a mannequin with a calibrated sound level meter. Participants reported demographic information, whether they had just come off the subway, the type of PLD and earphones used, and duration per day and days per week they used their PLDs. Based on measured free-field equivalent sound levels from PLD headphones and the reported PLD use, per day 58.2% of participants exceeded 85 dB A-weighted 8-hr equivalent sound levels (L(Aeq)), and per week 51.9% exceeded 85 dB A-weighted 40-hr equivalent continuous sound levels (L(Awkn)). The majority of PLD users exceeded recommended sound exposure limits, suggesting that they were at increased risk for noise-induced hearing loss. Analyses of the demographics of these participants and mode of transportation to campus failed to indicate any particular gender differences in PLD use or in mode of transportation influencing sound exposure.

Cultural and demographic factors influencing noise exposure estimates from use of portable listening devices in an urban environment.

PubMed

Fligor, Brian J; Levey, Sandra; Levey, Tania

2014-08-01

This study examined listening levels and duration of portable listening devices (PLDs) used by people with diversity of ethnicity, education, music genre, and PLD manufacturer. The goal was to estimate participants' PLD noise exposure and identify factors influencing user behavior. This study measured listening levels of 160 adults in 2 New York City locations: (a) a quiet college campus and (b) Union Square, a busy interchange. Participants completed a questionnaire regarding demographics and PLD use. Ordinary least squares regression was used to explore the significance of demographic and behavioral factors. Average listening level was 94.1 dBA, with 99 of 160 (61.9%) and 92 of 159 (57.5%) exceeding daily (L A8hn) and weekly (L Awkn) recommended exposure limit, respectively. African American participants listened at the highest average levels (99.8 dBA). A majority of PLD users exceeded recommended exposure levels. Factors significant for higher exposure were ethnicity and age; factors not significantly associated with exposure were gender, education, location, awareness of possible association between PLD use and noise-induced hearing loss, mode of transportation, device manufacturer, and music genre. Efforts to effect behavior changes to lessen noise-induced hearing loss risk from PLD use should be sensitive to the cultural differences within the targeted population.

Role of catechins on ET-1 induced stimulation of PLD and NADPH oxidase activities in pulmonary smooth muscle cells: Determination of the probable mechanism by molecular docking studies.

PubMed

Chakraborti, Sajal; Sarkar, Jaganmay; Bhuyan, Rajabrata; Chakraborti, Tapati

2017-12-05

Treatment of human pulmonary artery smooth muscle cells with ET-1 stimulated PLD and NADPH oxidase activities, which were inhibited upon pretreatment with bosentan (ET-1 receptor antagonist), FIPI (PLD inhibitor), apocynin (NADPH oxidase inhibitor) and EGCG & ECG (catechins having galloyl group), but not EGC & EC (catechins devoid of galloyl group). Herein, we determined the probable mechanism by which the galloyl group containing catechins inhibit ET-1 induced stimulation of PLD activity by molecular docking analyses based on our biochemical studies. ET-1 induced stimulation of PLD activity was inhibited by SecinH3 (inhibitor of cytohesin). Arf-6 and cytohesin-1 were associated in the cell membrane, which was not inhibited by the catechins during ET-1 treatment to the cells. However, EGCG and ECG inhibited binding of GTPγS with Arf-6 even in presence of cytohesin-1. The molecular docking analyses revealed that the galloyl group containing catechins (EGCG/ECG) with cytohesin1-Arf6GDP, but not the non-galloyl-containing catechins (EGC and EC), prevents GDP/GTP exchange in Arf-6 which seems to be an important mechanism for inhibition of ET-1 induced activation of PLD and subsequently increase in NADPH oxidase activities.

Efficacy of PLD-118, a Novel Inhibitor of Candida Isoleucyl-tRNA Synthetase, against Experimental Oropharyngeal and Esophageal Candidiasis Caused by Fluconazole-Resistant C. albicans

PubMed Central

Petraitis, Vidmantas; Petraitiene, Ruta; Kelaher, Amy M.; Sarafandi, Alia A.; Sein, Tin; Mickiene, Diana; Bacher, John; Groll, Andreas H.; Walsh, Thomas J.

2004-01-01

PLD-118, formerly BAY 10-8888, is a synthetic antifungal derivative of the naturally occurring β-amino acid cispentacin. We studied the activity of PLD-118 in escalating dosages against experimental oropharyngeal and esophageal candidiasis (OPEC) caused by fluconazole (FLC)-resistant Candida albicans in immunocompromised rabbits. Infection was established by fluconazole-resistant (MIC > 64 μg/ml) clinical isolates from patients with refractory esophageal candidiasis. Antifungal therapy was administered for 7 days. Study groups consisted of untreated controls; animals receiving PLD-118 at 4, 10, 25, or 50 mg/kg of body weight/day via intravenous (i.v.) twice daily (BID) injections; animals receiving FLC at 2 mg/kg/day via i.v. BID injections; and animals receiving desoxycholate amphotericin B (DAMB) i.v. at 0.5 mg/kg/day. PLD-118- and DAMB-treated animals showed a significant dosage-dependent clearance of C. albicans from the tongue, oropharynx, and esophagus in comparison to untreated controls (P ≤ 0.05, P ≤ 0.01, P ≤ 0.001, respectively), while FLC had no significant activity. PLD-118 demonstrated nonlinear plasma pharmacokinetics across the investigated dosage range, as was evident from a dose-dependent increase in plasma clearance and a dose-dependent decrease in the area under the plasma concentration-time curve. The biochemical safety profile was similar to that of FLC. In summary, PLD-118 demonstrated dosage-dependent antifungal activity and nonlinear plasma pharmacokinetics in treatment of experimental FLC-resistant oropharyngeal and esophageal candidiasis. PMID:15388459

Efficacy of PLD-118, a novel inhibitor of candida isoleucyl-tRNA synthetase, against experimental oropharyngeal and esophageal candidiasis caused by fluconazole-resistant C. albicans.

PubMed

Petraitis, Vidmantas; Petraitiene, Ruta; Kelaher, Amy M; Sarafandi, Alia A; Sein, Tin; Mickiene, Diana; Bacher, John; Groll, Andreas H; Walsh, Thomas J

2004-10-01

PLD-118, formerly BAY 10-8888, is a synthetic antifungal derivative of the naturally occurring beta-amino acid cispentacin. We studied the activity of PLD-118 in escalating dosages against experimental oropharyngeal and esophageal candidiasis (OPEC) caused by fluconazole (FLC)-resistant Candida albicans in immunocompromised rabbits. Infection was established by fluconazole-resistant (MIC > 64 microg/ml) clinical isolates from patients with refractory esophageal candidiasis. Antifungal therapy was administered for 7 days. Study groups consisted of untreated controls; animals receiving PLD-118 at 4, 10, 25, or 50 mg/kg of body weight/day via intravenous (i.v.) twice daily (BID) injections; animals receiving FLC at 2 mg/kg/day via i.v. BID injections; and animals receiving desoxycholate amphotericin B (DAMB) i.v. at 0.5 mg/kg/day. PLD-118- and DAMB-treated animals showed a significant dosage-dependent clearance of C. albicans from the tongue, oropharynx, and esophagus in comparison to untreated controls (P

From the Cover: Potentiation of Drug-Induced Phospholipidosis In Vitro through PEGlyated Graphene Oxide as the Nanocarrier.

PubMed

Yang, Liecheng; Zhong, Xiaoyan; Li, Qian; Zhang, Xihui; Wang, Yangyun; Yang, Kai; Zhang, Leshuai W

2017-03-01

Cationic amphiphilic drugs (CADs) are small molecules that can induce phospholipidosis (PLD), causing the intracellular accumulation of phospholipid in the lamellar bodies. Nanotechnology based drug delivery systems have been used widely, while it is unknown if drug-induced PLD (DIP) can be potentiated through drug retention by indigestible nanocarriers. Due to the high drug loading capacity of graphene, we investigated if PEGylated graphene oxide (PEG-GO) loaded with CAD could potentiate DIP. Tamoxifen induced the accumulation of NBD-PE, a fluorescence labeled phospholipid in human hepatoma HepG2 cells, while PEG-GO loaded with tamoxifen (PEG-GO/tamoxifen) further potentiated PLD. PEG-GO/tamoxifen induced more gene expression of PLD marker than tamoxifen alone. PEG-GO enhanced DIP was also observed for other CAD, indicating that nanocarrier potentiated DIP could be universal. More lamellar bodies were observed in PEG-GO/tamoxifen treated cells than tamoxifen alone by transmission electron microscopy. When compared with tamoxifen alone, PEG-GO/tamoxifen showed a delayed but potent PLD. In addition, the retarded PLD recovery by PEG-GO/tamoxifen indicated that the reversibility of DIP was interfered. Confocal microscopy revealed the increased number of lysosomes, greater expression of lysosomal associated membrane protein 2 (LAMP2) (a PLD marker), and an increase in the co-localization between lysosome/LAMP2 and NBD-PE by PEG-GO/tamoxifen rather than tamoxifen alone. Finally, we found that PEG-GO or/and tamoxifen-induced PLD seemed to have no correlation with autophagy. This research suggests pharmaceutical companies and regulatory agencies that if nanoparticles are used as the vectors for drug delivery, the adverse drug effects may be further potentiated probably through the long-term accumulation of nanocarriers. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Phosphatidic Acid Produced by RalA-activated PLD2 Stimulates Caveolae-mediated Endocytosis and Trafficking in Endothelial Cells.

PubMed

Jiang, Ying; Sverdlov, Maria S; Toth, Peter T; Huang, Long Shuang; Du, Guangwei; Liu, Yiyao; Natarajan, Viswanathan; Minshall, Richard D

2016-09-23

Caveolae are the primary route for internalization and transendothelial transport of macromolecules, such as insulin and albumin. Caveolae-mediated endocytosis is activated by Src-dependent caveolin-1 (Cav-1) phosphorylation and subsequent recruitment of dynamin-2 and filamin A (FilA), which facilitate vesicle fission and trafficking, respectively. Here, we tested the role of RalA and phospholipase D (PLD) signaling in the regulation of caveolae-mediated endocytosis and trafficking. The addition of albumin to human lung microvascular endothelial cells induced the activation of RalA within minutes, and siRNA-mediated down-regulation of RalA abolished fluorescent BSA uptake. Co-immunoprecipitation studies revealed that albumin induced the association between RalA, Cav-1, and FilA; however, RalA knockdown with siRNA did not affect FilA recruitment to Cav-1, suggesting that RalA was not required for FilA and Cav-1 complex formation. Rather, RalA probably facilitates caveolae-mediated endocytosis by activating downstream effectors. PLD2 was shown to be activated by RalA, and inhibition of PLD2 abolished Alexa-488-BSA uptake, indicating that phosphatidic acid (PA) generated by PLD2 may facilitate caveolae-mediated endocytosis. Furthermore, using a PA biosensor, GFP-PASS, we observed that BSA induced an increase in PA co-localization with Cav-1-RFP, which could be blocked by a dominant negative PLD2 mutant. Total internal reflection fluorescence microscopy studies of Cav-1-RFP also showed that fusion of caveolae with the basal plasma membrane was dependent on PLD2 activity. Thus, our results suggest that the small GTPase RalA plays an important role in promoting invagination and trafficking of caveolae, not by potentiating the association between Cav-1 and FilA but by stimulating PLD2-mediated generation of phosphatidic acid. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Reliability of Three Dimentional Pseudo-continuous Arterial Spin Labeling: A Volumetric Cerebral Perfusion Imaging with Different Post-labeling Time and Functional State in Health Adults.

PubMed

Liu, Meng-Qi; Chen, Zhi-Ye; Ma, Lin

2018-03-30

Objective To evaluate the reliability of three dimensional spiral fast spin echo pseudo-continuous arterial spin labeling (3D pc-ASL) in measuring cerebral blood flow (CBF) with different post-labeling delay time (PLD) in the resting state and the right finger taping state. Methods 3D pc-ASL and three dimensional T1-weighted fast spoiled gradient recalled echo (3D T1-FSPGR) sequence were applied to eight healthy subjects twice at the same time each day for one week interval. ASL data acquisition was performed with post-labeling delay time (PLD) 1.5 seconds and 2.0 seconds in the resting state and the right finger taping state respectively. CBF mapping was calculated and CBF value of both the gray matter (GM) and white matter (WM) was automatically extracted. The reliability was evaluated using the intraclass correlation coefficient (ICC) and Bland and Altman plot. Results ICC of the GM (0.84) and WM (0.92) was lower at PLD 1.5 seconds than that (GM, 0.88; WM, 0.94) at PLD 2.0 seconds in the resting state, and ICC of GM (0.88) was higher in the right finger taping state than that in the resting state at PLD 1.5 seconds. ICC of the GM and WM was 0.71 and 0.78 for PLD 1.5 seconds and PLD 2.0 seconds in the resting state at the first scan, and ICC of the GM and WM was 0.83 and 0.79 at the second scan, respectively. Conclusion This work demonstrated that 3D pc-ASL might be a reliable imaging technique to measure CBF over the whole brain at different PLD in the resting state or controlled state.

A matter of perception: Perceived socio-economic status and cortisol on the island of Utila, Honduras.

PubMed

García, Angela R; Gurven, Michael; Blackwell, Aaron D

2017-09-10

Numerous studies link low objective and subjective socioeconomic status (SES) to chronic activation of the hypothalamic pituitary adrenal (HPA) axis. Here, we examine associations between objective and subjective SES and diurnal salivary cortisol, a primary HPA component, as well as demographic and ecological predictors associated with SES perceptions and changes in diurnal cortisol. Participants were residents (age 18-79, n = 61) of Utila, a Honduran island where economic disparities are overt and geographically contained. Objective SES was measured as a composite of income, education, and occupation. Subjective SES was measured with a MacArthur ladder and a perceived lifestyle discrepancy (PLD) scale. Salivary cortisol was collected three times per day for two days. Questions addressing demographic, social, and household characteristics were assessed as predictors of PLD. Assessed independently, objective SES (P = .06) and PLD (P = .003) were associated with the steepness of diurnal cortisol changes, while PLD was also associated with higher cortisol area under the curve (AUC) (P = .036). Modeled together, only PLD predicted diurnal slope and AUC. PLD was associated with household sanitation, immigration status, food scarcity, objective SES, and owing money. Only access to sanitation and owing money had direct associations with cortisol that were not mediated by PLD. For adults on Utila, perceptions of unmet need outweigh other social and economic status factors in predicting cortisol AUC and slope. In addition, the unmediated effects of access to sanitation and owing money on cortisol suggest that these distinct aspects of inequality are important to consider when seeking to understand how inequality can impact HPA function. © 2017 Wiley Periodicals, Inc.

Molecular Effects of Doxorubicin on Choline Metabolism in Breast Cancer.

PubMed

Cheng, Menglin; Rizwan, Asif; Jiang, Lu; Bhujwalla, Zaver M; Glunde, Kristine

2017-08-01

Abnormal choline phospholipid metabolism is a hallmark of cancer. The magnetic resonance spectroscopy (MRS) detected total choline (tCho) signal can serve as an early noninvasive imaging biomarker of chemotherapy response in breast cancer. We have quantified the individual components of the tCho signal, glycerophosphocholine (GPC), phosphocholine (PC) and free choline (Cho), before and after treatment with the commonly used chemotherapeutic drug doxorubicin in weakly metastatic human MCF7 and triple-negative human MDA-MB-231 breast cancer cells. While the tCho concentration did not change following doxorubicin treatment, GPC significantly increased and PC decreased. Of the two phosphatidylcholine-specific PLD enzymes, only PLD1, but not PLD2, mRNA was down-regulated by doxorubicin treatment. For the two reported genes encoding GPC phosphodiesterase, the mRNA of GDPD6, but not GDPD5, decreased following doxorubicin treatment. mRNA levels of choline kinase α (ChKα), which converts Cho to PC, were reduced following doxorubicin treatment. PLD1 and ChKα protein levels decreased following doxorubicin treatment in a concentration dependent manner. Treatment with the PLD1 specific inhibitor VU0155069 sensitized MCF7 and MDA-MB-231 breast cancer cells to doxorubicin-induced cytotoxicity. Low concentrations of 100 nM of doxorubicin increased MDA-MB-231 cell migration. GDPD6, but not PLD1 or ChKα, silencing by siRNA abolished doxorubicin-induced breast cancer cell migration. Doxorubicin induced GPC increase and PC decrease are caused by reductions in PLD1, GDPD6, and ChKα mRNA and protein expression. We have shown that silencing or inhibiting these genes/proteins can promote drug effectiveness and reduce adverse drug effects. Our findings emphasize the importance of detecting PC and GPC individually. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Conversion of muscle fiber types in regenerating chicken muscles following cross-reinnervation.

PubMed

Kikuchi, T; Akiba, T; Ashmore, C R

1986-01-01

Slow-tonic anterior latissimus dorsi (ALD) and fast-twitch posterior latissimus dorsi (PLD) muscles of 7 to 10-day-old White Leghorn chickens were crushed and allowed to be reinnervated by their own nerve, or crushed and transplanted to the other side and allowed to be reinnervated by the nerve of the side to which they were transplanted. Following transplantation, changes in the weight of the muscle, fiber-type composition and innervation pattern during regeneration were investigated. Normal growth rate of PLD was about twice that of ALD. Regenerating PLD, however, atrophied rapidly after crushing and denervation whether innervated by its own nerve or the other nerve type, whereas ALD reinnervated by its own nerve showed marked hypertrophy. PLD fibers transformed rapidly to fast-twitch alpha or slow-tonic (ST) fibers when they were reinnervated by PLD or ALD nerve, respectively. When ALD fibers were reinnervated by their own nerve, they differentiated into ST fibers that were surrounded by smaller immature fibers. ALD fibers were, however, resistant to complete control by fast-twitch PLD nerve and contained a large number of slow fibers (ST and beta) long after transplantation. Slow fibers in regenerates were initially multiply innervated, but later transformed into fast-twitch alpha fibers that were focally innervated. The mode of differentiation and innervation pattern of different muscle fiber types in regenerating muscles are discussed.

Phospholipase D and phosphatidic acid mediate heat stress induced secondary metabolism in Ganoderma lucidum.

PubMed

Liu, Yong-Nan; Lu, Xiao-Xiao; Chen, Dai; Lu, Ya-Ping; Ren, Ang; Shi, Liang; Zhu, Jing; Jiang, Ai-Liang; Yu, Han-Shou; Zhao, Ming-Wen

2017-11-01

Phospholipid-mediated signal transduction plays a key role in responses to environmental changes, but little is known about the role of phospholipid signalling in microorganisms. Heat stress (HS) is one of the most important environmental factors. Our previous study found that HS could induce the biosynthesis of the secondary metabolites, ganoderic acids (GA). Here, we performed a comprehensive mass spectrometry-based analysis to investigate HS-induced lipid remodelling in Ganoderma lucidum. In particular, we observed a significant accumulation of phosphatidic acid (PA) on HS. Further genetic tests in which pld-silencing strains were constructed demonstrated that the accumulation of PA is dependent on HS-activated phospholipase D (PLD) hydrolysing phosphatidylethanolamine. Furthermore, we determined the role of PLD and PA in HS-induced secondary metabolism in G. lucidum. Exogenous 1-butanol, which decreased PLD-mediated formation of PA, reverses the increased GA biosynthesis that was elicited by HS. The pld-silenced strains partly blocked HS-induced GA biosynthesis, and this block can be reversed by adding PA. Taken together, our results suggest that PLD and PA are involved in the regulation of HS-induced secondary metabolism in G. lucidum. Our findings provide key insights into how microorganisms respond to heat stress and then consequently accumulate secondary metabolites by phospholipid remodelling. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

A non-mitotic role for Aurora kinase A as a direct activator of cell migration upon interaction with PLD, FAK and Src

PubMed Central

Mahankali, Madhu; Henkels, Karen M.; Speranza, Francis; Gomez-Cambronero, Julian

2015-01-01

ABSTRACT Timely activation of Aurora kinase A (AURA, also known as AURKA) is vital for centrosome formation and the progression of mitosis. Nonetheless, it is still unclear if and when other cellular functions are activated by AURA. We report here that Src phosphorylates and activates AURA at T288, and AURA also activates focal adhesion kinase (FAK, also known as PTK2), leading to initiation of cell movement. An additional and new way by which AURA is regulated, is by phospholipase D2 (PLD2), which causes AURA activation. In addition, AURA phosphorylates PLD, so both proteins engage in a positive reinforcement loop. AURA and PLD2 form a protein–protein complex and colocalize to cytoplasmic regions in cells. The reason why PLD activates AURA is because of the production of phosphatidic acid by the lipase, which binds directly to AURA, with the region E171–E211 projected to be a phosphatidic-acid-binding pocket. Furthermore, this direct interaction with phosphatidic acid enhances tubulin polymerization and cooperates synergistically with AURA, FAK and Src in yielding a fully effectual cellular migration. Thus, Src and FAK, and PLD and phosphatidic acid are new upstream regulators of AURA that mediate its role in the non-mitotic cellular function of cell migration. PMID:25501815

Utilizing pulsed laser deposition lateral inhomogeneity as a tool in combinatorial material science.

PubMed

Keller, David A; Ginsburg, Adam; Barad, Hannah-Noa; Shimanovich, Klimentiy; Bouhadana, Yaniv; Rosh-Hodesh, Eli; Takeuchi, Ichiro; Aviv, Hagit; Tischler, Yaakov R; Anderson, Assaf Y; Zaban, Arie

2015-04-13

Pulsed laser deposition (PLD) is widely used in combinatorial material science, as it enables rapid fabrication of different composite materials. Nevertheless, this method was usually limited to small substrates, since PLD deposition on large substrate areas results in severe lateral inhomogeneity. A few technical solutions for this problem have been suggested, including the use of different designs of masks, which were meant to prevent inhomogeneity in the thickness, density, and oxidation state of a layer, while only the composition is allowed to be changed. In this study, a possible way to take advantage of the large scale deposition inhomogeneity is demonstrated, choosing an iron oxide PLD-deposited library with continuous compositional spread (CCS) as a model system. An Fe₂O₃-Nb₂O₅ library was fabricated using PLD, without any mask between the targets and the substrate. The library was measured using high-throughput scanners for electrical, structural, and optical properties. A decrease in electrical resistivity that is several orders of magnitude lower than pure α-Fe₂O₃ was achieved at ∼20% Nb-O (measured at 47 and 267 °C) but only at points that are distanced from the center of the PLD plasma plume. Using hierarchical clustering analysis, we show that the PLD inhomogeneity can be used as an additional degree of freedom, helping, in this case, to achieve iron oxide with much lower resistivity.

ATM inhibition induces synthetic lethality and enhances sensitivity of PTEN-deficient breast cancer cells to cisplatin.

PubMed

Li, Ke; Yan, Huaying; Guo, Wenhao; Tang, Mei; Zhao, Xinyu; Tong, Aiping; Peng, Yong; Li, Qintong; Yuan, Zhu

2018-05-01

PTEN deficiency often causes defects in DNA damage repair. Currently, effective therapies for breast cancer are lacking. ATM is an attractive target for cancer treatment. Previous studies suggested a synthetic lethality between PTEN and PARP. However, the synthetically lethal interaction between PTEN and ATM in breast cancer has not been reported. Moreover, the mechanism remains elusive. Here, using KU-60019, an ATM kinase inhibitor, we investigated ATM inhibition as a synthetically lethal strategy to target breast cancer cells with PTEN defects. We found that KU-60019 preferentially sensitizes PTEN-deficient MDA-MB-468 breast cancer cells to cisplatin, though it also slightly enhances sensitivity of PTEN wild-type breast cancer cells. The increased cytotoxic sensitivity is associated with apoptosis, as evidenced by flow cytometry and PARP cleavage. Additionally, the increase of DNA damage accumulation due to the decreased capability of DNA repair, as indicated by γ-H2AX and Rad51 foci, also contributed to this selective cytotoxicity. Mechanistically, compared with PTEN wild-type MDA-MB-231 cells, PTEN-deficient MDA-MB-468 cells have lower level of Rad51, higher ATM kinase activity, and display the elevated level of DNA damage. Moreover, these differences could be further enlarged by cisplatin. Our findings suggest that ATM is a promising target for PTEN-defective breast cancer. Copyright © 2018 Elsevier Inc. All rights reserved.

Clinical Trials with Pegylated Liposomal Doxorubicin in the Treatment of Ovarian Cancer

PubMed Central

Pisano, Carmela; Cecere, Sabrina Chiara; Di Napoli, Marilena; Cavaliere, Carla; Tambaro, Rosa; Facchini, Gaetano; Losito, Simona; Pizzolorusso, Antonio; Pignata, Sandro

2013-01-01

Among the pharmaceutical options available for treatment of ovarian cancer, increasing attention has been progressively focused on pegylated liposomal doxorubicin (PLD), whose unique formulation prolongs the persistence of the drug in the circulation and potentiates intratumor accumulation. Pegylated liposomal doxorubicin (PLD) has become a major component in the routine management of epithelial ovarian cancer. In 1999 it was first approved for platinum-refractory ovarian cancer and then received full approval for platinum-sensitive recurrent disease in 2005. PLD remains an important therapeutic tool in the management of recurrent ovarian cancer in 2012. Recent interest in PLD/carboplatin combination therapy has been the object of phase III trials in platinum-sensitive and chemonaïve ovarian cancer patients reporting response rates, progressive-free survival, and overall survival similar to other platinum-based combinations, but with a more favorable toxicity profile and convenient dosing schedule. This paper summarizes data clarifying the role of pegylated liposomal doxorubicin (PLD) in ovarian cancer, as well as researches focusing on adding novel targeted drugs to this cytotoxic agent. PMID:23577259

Prion-like domains in RNA binding proteins are essential for building subnuclear paraspeckles

PubMed Central

Hennig, Sven; Kong, Geraldine; Mannen, Taro; Sadowska, Agata; Kobelke, Simon; Blythe, Amanda; Knott, Gavin J.; Iyer, K. Swaminathan; Ho, Diwei; Newcombe, Estella A.; Hosoki, Kana; Goshima, Naoki; Kawaguchi, Tetsuya; Hatters, Danny; Trinkle-Mulcahy, Laura; Hirose, Tetsuro; Bond, Charles S.

2015-01-01

Prion-like domains (PLDs) are low complexity sequences found in RNA binding proteins associated with the neurodegenerative disorder amyotrophic lateral sclerosis. Recently, PLDs have been implicated in mediating gene regulation via liquid-phase transitions that drive ribonucleoprotein granule assembly. In this paper, we report many PLDs in proteins associated with paraspeckles, subnuclear bodies that form around long noncoding RNA. We mapped the interactome network of paraspeckle proteins, finding enrichment of PLDs. We show that one protein, RBM14, connects key paraspeckle subcomplexes via interactions mediated by its PLD. We further show that the RBM14 PLD, as well as the PLD of another essential paraspeckle protein, FUS, is required to rescue paraspeckle formation in cells in which their endogenous counterpart has been knocked down. Similar to FUS, the RBM14 PLD also forms hydrogels with amyloid-like properties. These results suggest a role for PLD-mediated liquid-phase transitions in paraspeckle formation, highlighting this nuclear body as an excellent model system for understanding the perturbation of such processes in neurodegeneration. PMID:26283796

Photothermal laser deflection, an innovative technique to measure particles in exhausts

NASA Astrophysics Data System (ADS)

Hess, Cecil F.

1993-10-01

Photothermal Laser Deflection (PLD) is an analytical technique to measure in real-time the mass concentration of particles and gaseous exhaust pollutants in a variety of combustion devices (e.g., gas turbine engines and rockets). PLD uses a pump laser to locally heat the particle or gaseous species, thus changing the refractive index of the surrounding gas to form a thermal lens. A probe laser beam travelling through the thermal lens is temporarily deflected, and the amount of deflection is proportional to the species mass concentration. The experiments and analyses conducted during phase 1 demonstrated the feasibility of PLD in measuring the mass concentration of both soot particles and NO2 at a repetition rate of 25 HZ. PLD response was linear at soot concentrations from 0.3 to 10 mg/cubic meters at NO2 concentrations from approximately 6 to 208 ppm. Strategies to measure lower concentrations have been defined and include focusing the probe beam onto the face of the bi-cell detector. The large dynamic range, fast acquisition rate, and ability to measure particulate and gaseous pollutants makes PLD superior to other available methods.

Rare coding variants in Phospholipase D3 (PLD3) confer risk for Alzheimer's disease

PubMed Central

Cruchaga, Carlos; Benitez, Bruno A.; Cai, Yefei; Guerreiro, Rita; Harari, Oscar; Norton, Joanne; Budde, John; Bertelsen, Sarah; Jeng, Amanda T.; Cooper, Breanna; Skorupa, Tara; Carrell, David; Levitch, Denise; Hsu, Simon; Choi, Jiyoon; Ryten, Mina; Sassi, Celeste; Bras, Jose; Gibbs, Raphael J.; Hernandez, Dena G.; Lupton, Michelle K.; Powell, John; Forabosco, Paola; Ridge, Perry G.; Corcoran, Christopher D.; Tschanz, JoAnn T.; Norton, Maria C.; Munger, Ronald G.; Schmutz, Cameron; Leary, Maegan; Demirci, F. Yesim; Bamne, Mikhil N.; Wang, Xingbin; Lopez, Oscar L.; Ganguli, Mary; Medway, Christopher; Turton, James; Lord, Jenny; Braae, Anne; Barber, Imelda; Brown, Kristelle; Pastor, Pau; Lorenzo-Betancor, Oswaldo; Brkanac, Zoran; Scott, Erick; Topol, Eric; Morgan, Kevin; Rogaeva, Ekaterina; Singleton, Andy; Hardy, John; Kamboh, M. Ilyas; George-Hyslop, Peter St; Cairns, Nigel; Morris, John C.; Kauwe, John S.K.; Goate, Alison M.

2014-01-01

Genome-wide association studies (GWAS) have identified several risk variants for late-onset Alzheimer's disease (LOAD)1,2. These common variants have replicable but small effects on LOAD risk and generally do not have obvious functional effects. Low-frequency coding variants, not detected by GWAS, are predicted to include functional variants with larger effects on risk. To identify low frequency coding variants with large effects on LOAD risk, we performed whole exome-sequencing (WES) in 14 large LOAD families and follow-up analyses of the candidate variants in several large case-control datasets. A rare variant in PLD3 (phospholipase-D family, member 3, rs145999145; V232M) segregated with disease status in two independent families and doubled risk for AD in seven independent case-control series (V232M meta-analysis; OR= 2.10, CI=1.47-2.99; p= 2.93×10-5, 11,354 cases and controls of European-descent). Gene-based burden analyses in 4,387 cases and controls of European-descent and 302 African American cases and controls, with complete sequence data for PLD3, indicate that several variants in this gene increase risk for AD in both populations (EA: OR= 2.75, CI=2.05-3.68; p=1.44×10-11, AA: OR= 5.48, CI=1.77-16.92; p=1.40×10-3). PLD3 is highly expressed in brain regions vulnerable to AD pathology, including hippocampus and cortex, and is expressed at lower levels in neurons from AD brains compared to control brains (p=8.10×10-10). Over-expression of PLD3 leads to a significant decrease in intracellular APP and extracellular Aβ42 and Aβ40, while knock-down of PLD3 leads to a significant increase in extracellular Aβ42 and Aβ40. Together, our genetic and functional data indicate that carriers of PLD3 coding variants have a two-fold increased risk for LOAD and that PLD3 influences APP processing. This study provides an example of how densely affected families may be used to identify rare variants with large effects on risk for disease or other complex traits. PMID:24336208

The power of in situ pulsed laser deposition synchrotron characterization for the detection of domain formation during growth of Ba0.5Sr0.5TiO3 on MgO.

PubMed

Bauer, Sondes; Lazarev, Sergey; Molinari, Alan; Breitenstein, Andreas; Leufke, Philipp; Kruk, Robert; Hahn, Horst; Baumbach, Tilo

2014-03-01

A highly sophisticated pulsed laser deposition (PLD) chamber has recently been installed at the NANO beamline at the synchrotron facility ANKA (Karlsruhe, Germany), which allows for comprehensive studies on the PLD growth process of dielectric, ferroelectric and ferromagnetic thin films in epitaxial oxide heterostructures or even multilayer systems by combining in situ reflective high-energy diffraction with the in situ synchrotron high-resolution X-ray diffraction and surface diffraction methods. The modularity of the in situ PLD chamber offers the opportunity to explore the microstructure of the grown thin films as a function of the substrate temperature, gas pressure, laser fluence and target-substrate separation distance. Ba0.5Sr0.5TiO3 grown on MgO represents the first system that is grown in this in situ PLD chamber and studied by in situ X-ray reflectivity, in situ two-dimensional reciprocal space mapping of symmetric X-ray diffraction and acquisition of time-resolved diffraction profiles during the ablation process. In situ PLD synchrotron investigation has revealed the occurrence of structural distortion as well as domain formation and misfit dislocation which all depend strongly on the film thickness. The microstructure transformation has been accurately detected with a time resolution of 1 s. The acquisition of two-dimensional reciprocal space maps during the PLD growth has the advantage of simultaneously monitoring the changes of the crystalline structure as well as the formation of defects. The stability of the morphology during the PLD growth is demonstrated to be remarkably affected by the film thickness. A critical thickness for the domain formation in Ba0.5Sr0.5TiO3 grown on MgO could be determined from the acquisition of time-resolved diffraction profiles during the PLD growth. A splitting of the diffraction peak into two distinguishable peaks has revealed a morphology change due to modification of the internal strain during growth.

[Injuries and fatalities caused by gas-/warning weapons].

PubMed

Maxeiner, H; Schneider, V

1989-01-01

Detailed report of 5 cases of violation with gas or warning firearms, 3 of them lethal. In one case a modified weapon (elongated barrel) and steel bullets were used, resulting in shot of the head with retained missile and lethal bleeding. In the other cases, regular weapons (8 or 9 mm cartridges) were used for contact shots; violation occurred only by the effect of powder gases. One of these cases was a suizide (lethal temporal gunshot), in the other cases shots by another person: a) shot against the arm with large soft-tissue damage (survived); b) and c) shot against the neck with exceeding rupture of the soft tissues, minimal damage of the neck arteries and in one cases bilateral tears of the hypopharynx. In this case a delayed death after primarily well operated injury occurred after 12 days by bleeding into the airways from ruptured external carotid artery.

Phospholipase D2 Is Involved in the Formation of Golgi Tubules and ArfGAP1 Recruitment

PubMed Central

Martínez-Martínez, Narcisa; Martínez-Alonso, Emma; Ballesta, José; Martínez-Menárguez, José A.

2014-01-01

Lipids and lipid-modifying enzymes play a key role in the biogenesis, maintenance and fission of transport carriers in the secretory and endocytic pathways. In the present study we demonstrate that phosphatidic acid generated by phospholipase D2 (PLD2) is involved in the formation of Golgi tubules. The main evidence to support this is: 1) inhibitors of phosphatidic acid formation and PLD2 depletion inhibit the formation of tubules containing resident enzymes and regulators of intra-Golgi transport in a low temperature (15°C) model of Golgi tubulation but do not affect brefeldin A-induced tubules, 2) inhibition of PLD2 enzymatic activity and PLD2 depletion in cells cultured under physiological conditions (37°C) induce the formation of tubules specifically containing Golgi matrix proteins, and, 3) over-expression of PLD2 induces the formation of a tubular network. In addition, it was found that the generation of this lipid by the isoenzyme is necessary for ArfGAP1 recruitment to Golgi membranes. These results suggest that both proteins are involved in the molecular mechanisms which drive the formation of different types of Golgi tubules. PMID:25354038

Microstructural, nanomechanical, and microtribological properties of Pb thin films prepared by pulsed laser deposition and thermal evaporation techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Broitman, Esteban, E-mail: esbro@ifm.liu.se; Flores-Ruiz, Francisco J.; Di Giulio, Massimo

2016-03-15

In this work, the authors compare the morphological, structural, nanomechanical, and microtribological properties of Pb films deposited by thermal evaporation (TE) and pulsed laser deposition (PLD) techniques onto Si (111) substrates. Films were investigated by scanning electron microscopy, surface probe microscopy, and x-ray diffraction in θ-2θ geometry to determine their morphology, root-mean-square (RMS) roughness, and microstructure, respectively. TE films showed a percolated morphology with densely packed fibrous grains while PLD films had a granular morphology with a columnar and tightly packed structure in accordance with the zone growth model of Thornton. Moreover, PLD films presented a more polycrystalline structure withmore » respect to TE films, with RMS roughness of 14 and 10 nm, respectively. Hardness and elastic modulus vary from 2.1 to 0.8 GPa and from 14 to 10 GPa for PLD and TE films, respectively. A reciprocal friction test has shown that PLD films have lower friction coefficient and wear rate than TE films. Our study has demonstrated for first time that, at the microscale, Pb films do not show the same simple lubricious properties measured at the macroscale.« less

Recombinant M. bovis BCG expressing the PLD protein promotes survival in mice challenged with a C. pseudotuberculosis virulent strain.

PubMed

Leal, Karen Silva; de Oliveira Silva, Mara Thais; de Fátima Silva Rezende, Andréa; Bezerra, Francisco Silvestre Brilhante; Begnini, Karine; Seixas, Fabiana; Collares, Tiago; Dellagostin, Odir; Portela, Ricardo Wagner; de Carvalho Azevedo, Vasco Ariston; Borsuk, Sibele

2018-06-14

The aim of this study was to evaluate the survival of mice inoculated with M. bovis BCG Pasteur recombinant expressing the PLD protein and challenged with a C. pseudotuberculosis virulent strain. Four groups were immunized with a sterile 0.9% saline solution (G1), 10 6  CFU of M. bovis BCG Pasteur (G2), 10 6  CFU of M. bovis BCG/pld (G3) or 10 6  CFU of M. bovis BCG/pld with a booster with rPLD (G4) and challenged with 10 4 CFU of C. pseudotuberculosis MIC-6 strain. The highest survival rate of 88% was observed in G4, followed by 77% in G3 and 66% in G2. A significant statistical difference was observed in the levels of cytokines IFN-γ and IL-10 in vaccinated groups (G3 and G4) when compared with the control group (G1) (p < 0.05). The results seem promising as the recombinant vaccine elicited a cellular immune response and provided significant survival after a high virulent challenge. Copyright © 2018 Elsevier Ltd. All rights reserved.

Differential Expression of Ccn4 and Other Genes Between Metastatic and Non-metastatic EL4 Mouse Lymphoma Cells

PubMed Central

S. CHAHAL, MANPREET; TERESA KU, H.; ZHANG, ZHIHONG; M. LEGASPI, CHRISTIAN; LUO, ANGELA; M. HOPKINS, MANDI; E. MEIER, KATHRYN

2016-01-01

Background: Previous work characterized variants of the EL4 murine lymphoma cell line. Some are non-metastatic, and others metastatic, in syngenic mice. In addition, metastatic EL4 cells were stably transfected with phospholipase D2 (PLD2), which further enhanced metastasis. Materials and Methods: Microarray analyses of mRNA expression was performed for non-metastatic, metastatic, and PLD2-expressing metastatic EL4 cells. Results: Many differences were observed between non-metastatic and metastatic cell lines. One of the most striking new findings was up-regulation of mRNA for the matricellular protein WNT1-inducible signaling pathway protein 1 (CCN4) in metastatic cells; increased protein expression was verified by immunoblotting and immunocytochemistry. Other differentially expressed genes included those for reproductive homeobox 5 (Rhox5; increased in metastatic) and cystatin 7 (Cst7; decreased in metastatic). Differences between PLD2-expressing and parental cell lines were limited but included the signaling proteins Ras guanyl releasing protein 1 (RGS18; increased with PLD2) and suppressor of cytokine signaling 2 (SOCS2; decreased with PLD2). Conclusion: The results provide insights into signaling pathways potentially involved in conferring metastatic ability on lymphoma cells. PMID:27807066

An update on the pathophysiology and management of polycystic liver disease.

PubMed

Wong, May Yw; McCaughan, Geoffrey W; Strasser, Simone I

2017-06-01

Polycystic liver disease (PLD) is characterized by the presence of multiple cholangiocyte-derived hepatic cysts that progressively replace liver tissue. They are classified as an inherited ciliopathy /cholangiopathy as pathology exists at the level of the primary cilia of cholangiocytes. Aberrant expression of the proteins in primary cilia can impair their structures and functions, thereby promoting cystogenesis. Areas covered: This review begins by looking at the epidemiology of PLD and its natural history. It then describes the pathophysiology and corresponding potential treatment strategies for PLD. Expert commentary: Traditionally, therapies for symptomatic PLD have been limited to symptomatic management and surgical interventions. Such techniques are not completely effective, do not alter the natural history of the disease, and are linked with high rate of re-accumulation of cysts. As a result, there has been a push for drugs targeted at abnormal cellular signaling cascades to address deregulated proliferation, cell dedifferentiation, apoptosis and fluid secretion. Currently, the only available drug treatments that halt disease progression and improve quality of life in PLD patients are somatostatin analogues. Numerous preclinical studies suggest that targeting components of the signaling pathways that influence cyst development can ameliorate growth of hepatic cysts.

Molecular Basis of Cardioprotective Effect of Antioxidant Vitamins in Myocardial Infarction

PubMed Central

Rodrigo, Ramón; Feliú, Felipe; Hasson, Daniel

2013-01-01

Acute myocardial infarction (AMI) is the leading cause of mortality worldwide. Major advances in the treatment of acute coronary syndromes and myocardial infarction, using cardiologic interventions, such as thrombolysis or percutaneous coronary angioplasty (PCA) have improved the clinical outcome of patients. Nevertheless, as a consequence of these procedures, the ischemic zone is reperfused, giving rise to a lethal reperfusion event accompanied by increased production of reactive oxygen species (oxidative stress). These reactive species attack biomolecules such as lipids, DNA, and proteins enhancing the previously established tissue damage, as well as triggering cell death pathways. Studies on animal models of AMI suggest that lethal reperfusion accounts for up to 50% of the final size of a myocardial infarct, a part of the damage likely to be prevented. Although a number of strategies have been aimed at to ameliorate lethal reperfusion injury, up to date the beneficial effects in clinical settings have been disappointing. The use of antioxidant vitamins could be a suitable strategy with this purpose. In this review, we propose a systematic approach to the molecular basis of the cardioprotective effect of antioxidant vitamins in myocardial ischemia-reperfusion injury that could offer a novel therapeutic opportunity against this oxidative tissue damage. PMID:23936799

Larval dispersal in three coral reef decapod species: Influence of larval duration on the metapopulation structure.

PubMed

Sanvicente-Añorve, Laura; Zavala-Hidalgo, Jorge; Allende-Arandía, Eugenia; Hermoso-Salazar, Margarita

2018-01-01

Most coral-associated decapod species have non-migratory adult populations and depend on their planktonic larvae for dispersal. This study examined the metapopulation structure of three decapod species with different pelagic larval duration (PLD) from twelve coral reef complexes of the Gulf of Mexico. The dispersion of larvae was analyzed through the use of a realistic numerical simulation of the Gulf of Mexico with the Hybrid Coordinate Ocean Model. To study the transport and dispersion of particles in near-surface waters, a particle-tracking subroutine was run using as input the currents from the model. The simulation consisted of the launch of 100 passive particles (virtual larvae) every 24 hours from each reef throughout five years, and tracked for as long as 210 days. Results indicated that species with a short PLD, Mithraculus sculptus (PLD 8‒13 days), had a weak connection among the reefs, but higher self-recruitment, especially on the narrow western shelf. The species with a longer PLD, Dromia erythropus (28‒30 days), had a stronger connection among neighboring reefs (< 300 km). Finally, the species with an even longer PLD, Stenopus hispidus (123‒210 days), had a wider potential distribution than the other species. Circulation on synoptic, seasonal and interannual scales had differential effects on the larval dispersal of each species. The metapopulation structure of M. sculptus and D. erythropus seemed to combine features of the non-equilibrium and the patchy models, whereas that of S. hispidus presumably fit to a patchy model. These findings support previous observations that indicate that species with longer PLD tend to occupy larger areas than species with short PLD, although recruitment of juveniles to the adult populations will also depend on other factors, such as the availability of suitable habitats and the ability to colonize them.

Rare coding variants in the phospholipase D3 gene confer risk for Alzheimer's disease

NASA Astrophysics Data System (ADS)

2014-01-01

Genome-wide association studies (GWAS) have identified several risk variants for late-onset Alzheimer's disease (LOAD). These common variants have replicable but small effects on LOAD risk and generally do not have obvious functional effects. Low-frequency coding variants, not detected by GWAS, are predicted to include functional variants with larger effects on risk. To identify low-frequency coding variants with large effects on LOAD risk, we carried out whole-exome sequencing (WES) in 14 large LOAD families and follow-up analyses of the candidate variants in several large LOAD case-control data sets. A rare variant in PLD3 (phospholipase D3; Val232Met) segregated with disease status in two independent families and doubled risk for Alzheimer's disease in seven independent case-control series with a total of more than 11,000 cases and controls of European descent. Gene-based burden analyses in 4,387 cases and controls of European descent and 302 African American cases and controls, with complete sequence data for PLD3, reveal that several variants in this gene increase risk for Alzheimer's disease in both populations. PLD3 is highly expressed in brain regions that are vulnerable to Alzheimer's disease pathology, including hippocampus and cortex, and is expressed at significantly lower levels in neurons from Alzheimer's disease brains compared to control brains. Overexpression of PLD3 leads to a significant decrease in intracellular amyloid-β precursor protein (APP) and extracellular Aβ42 and Aβ40 (the 42- and 40-residue isoforms of the amyloid-β peptide), and knockdown of PLD3 leads to a significant increase in extracellular Aβ42 and Aβ40. Together, our genetic and functional data indicate that carriers of PLD3 coding variants have a twofold increased risk for LOAD and that PLD3 influences APP processing. This study provides an example of how densely affected families may help to identify rare variants with large effects on risk for disease or other complex traits.

Larval dispersal in three coral reef decapod species: Influence of larval duration on the metapopulation structure

PubMed Central

Zavala-Hidalgo, Jorge; Allende-Arandía, Eugenia; Hermoso-Salazar, Margarita

2018-01-01

Most coral-associated decapod species have non-migratory adult populations and depend on their planktonic larvae for dispersal. This study examined the metapopulation structure of three decapod species with different pelagic larval duration (PLD) from twelve coral reef complexes of the Gulf of Mexico. The dispersion of larvae was analyzed through the use of a realistic numerical simulation of the Gulf of Mexico with the Hybrid Coordinate Ocean Model. To study the transport and dispersion of particles in near-surface waters, a particle-tracking subroutine was run using as input the currents from the model. The simulation consisted of the launch of 100 passive particles (virtual larvae) every 24 hours from each reef throughout five years, and tracked for as long as 210 days. Results indicated that species with a short PLD, Mithraculus sculptus (PLD 8‒13 days), had a weak connection among the reefs, but higher self-recruitment, especially on the narrow western shelf. The species with a longer PLD, Dromia erythropus (28‒30 days), had a stronger connection among neighboring reefs (< 300 km). Finally, the species with an even longer PLD, Stenopus hispidus (123‒210 days), had a wider potential distribution than the other species. Circulation on synoptic, seasonal and interannual scales had differential effects on the larval dispersal of each species. The metapopulation structure of M. sculptus and D. erythropus seemed to combine features of the non-equilibrium and the patchy models, whereas that of S. hispidus presumably fit to a patchy model. These findings support previous observations that indicate that species with longer PLD tend to occupy larger areas than species with short PLD, although recruitment of juveniles to the adult populations will also depend on other factors, such as the availability of suitable habitats and the ability to colonize them. PMID:29558478

Rare coding variants in the phospholipase D3 gene confer risk for Alzheimer's disease.

PubMed

Cruchaga, Carlos; Karch, Celeste M; Jin, Sheng Chih; Benitez, Bruno A; Cai, Yefei; Guerreiro, Rita; Harari, Oscar; Norton, Joanne; Budde, John; Bertelsen, Sarah; Jeng, Amanda T; Cooper, Breanna; Skorupa, Tara; Carrell, David; Levitch, Denise; Hsu, Simon; Choi, Jiyoon; Ryten, Mina; Sassi, Celeste; Bras, Jose; Gibbs, Raphael J; Hernandez, Dena G; Lupton, Michelle K; Powell, John; Forabosco, Paola; Ridge, Perry G; Corcoran, Christopher D; Tschanz, JoAnn T; Norton, Maria C; Munger, Ronald G; Schmutz, Cameron; Leary, Maegan; Demirci, F Yesim; Bamne, Mikhil N; Wang, Xingbin; Lopez, Oscar L; Ganguli, Mary; Medway, Christopher; Turton, James; Lord, Jenny; Braae, Anne; Barber, Imelda; Brown, Kristelle; Pastor, Pau; Lorenzo-Betancor, Oswaldo; Brkanac, Zoran; Scott, Erick; Topol, Eric; Morgan, Kevin; Rogaeva, Ekaterina; Singleton, Andy; Hardy, John; Kamboh, M Ilyas; George-Hyslop, Peter St; Cairns, Nigel; Morris, John C; Kauwe, John S K; Goate, Alison M

2014-01-23

Genome-wide association studies (GWAS) have identified several risk variants for late-onset Alzheimer's disease (LOAD). These common variants have replicable but small effects on LOAD risk and generally do not have obvious functional effects. Low-frequency coding variants, not detected by GWAS, are predicted to include functional variants with larger effects on risk. To identify low-frequency coding variants with large effects on LOAD risk, we carried out whole-exome sequencing (WES) in 14 large LOAD families and follow-up analyses of the candidate variants in several large LOAD case-control data sets. A rare variant in PLD3 (phospholipase D3; Val232Met) segregated with disease status in two independent families and doubled risk for Alzheimer's disease in seven independent case-control series with a total of more than 11,000 cases and controls of European descent. Gene-based burden analyses in 4,387 cases and controls of European descent and 302 African American cases and controls, with complete sequence data for PLD3, reveal that several variants in this gene increase risk for Alzheimer's disease in both populations. PLD3 is highly expressed in brain regions that are vulnerable to Alzheimer's disease pathology, including hippocampus and cortex, and is expressed at significantly lower levels in neurons from Alzheimer's disease brains compared to control brains. Overexpression of PLD3 leads to a significant decrease in intracellular amyloid-β precursor protein (APP) and extracellular Aβ42 and Aβ40 (the 42- and 40-residue isoforms of the amyloid-β peptide), and knockdown of PLD3 leads to a significant increase in extracellular Aβ42 and Aβ40. Together, our genetic and functional data indicate that carriers of PLD3 coding variants have a twofold increased risk for LOAD and that PLD3 influences APP processing. This study provides an example of how densely affected families may help to identify rare variants with large effects on risk for disease or other complex traits.

Computational identification of a phospholipidosis toxicophore using (13)C and (15)N NMR-distance based fingerprints.

PubMed

Slavov, Svetoslav H; Wilkes, Jon G; Buzatu, Dan A; Kruhlak, Naomi L; Willard, James M; Hanig, Joseph P; Beger, Richard D

2014-12-01

Modified 3D-SDAR fingerprints combining (13)C and (15)N NMR chemical shifts augmented with inter-atomic distances were used to model the potential of chemicals to induce phospholipidosis (PLD). A curated dataset of 328 compounds (some of which were cationic amphiphilic drugs) was used to generate 3D-QSDAR models based on tessellations of the 3D-SDAR space with grids of different density. Composite PLS models averaging the aggregated predictions from 100 fully randomized individual models were generated. On each of the 100 runs, the activities of an external blind test set comprised of 294 proprietary chemicals were predicted and averaged to provide composite estimates of their PLD-inducing potentials (PLD+ if PLD is observed, otherwise PLD-). The best performing 3D-QSDAR model utilized a grid with a density of 8ppm×8ppm in the C-C region, 8ppm×20ppm in the C-N region and 20ppm×20ppm in the N-N region. The classification predictive performance parameters of this model evaluated on the basis of the external test set were as follows: accuracy=0.70, sensitivity=0.73 and specificity=0.66. A projection of the most frequently occurring bins on the standard coordinate space suggested a toxicophore composed of an aromatic ring with a centroid 3.5-7.5Å distant from an amino-group. The presence of a second aromatic ring separated by a 4-5Å spacer from the first ring and at a distance of between 5.5Å and 7Å from the amino-group was also associated with a PLD+ effect. These models provide comparable predictive performance to previously reported models for PLD with the added benefit of being based entirely on non-confidential, publicly available training data and with good predictive performance when tested in a rigorous, external validation exercise. Published by Elsevier Ltd.

Method and apparatus for detecting and determining event characteristics with reduced data collection

NASA Technical Reports Server (NTRS)

Totman, Peter D. (Inventor); Everton, Randy L. (Inventor); Egget, Mark R. (Inventor); Macon, David J. (Inventor)

2007-01-01

A method and apparatus for detecting and determining event characteristics such as, for example, the material failure of a component, in a manner which significantly reduces the amount of data collected. A sensor array, including a plurality of individual sensor elements, is coupled to a programmable logic device (PLD) configured to operate in a passive state and an active state. A triggering event is established such that the PLD records information only upon detection of the occurrence of the triggering event which causes a change in state within one or more of the plurality of sensor elements. Upon the occurrence of the triggering event, the change in state of the one or more sensor elements causes the PLD to record in memory which sensor element detected the event and at what time the event was detected. The PLD may be coupled with a computer for subsequent downloading and analysis of the acquired data.

Mitochondrial Cardiomyopathy Caused by Elevated Reactive Oxygen Species and Impaired Cardiomyocyte Proliferation.

PubMed

Zhang, Donghui; Li, Yifei; Heims-Waldron, Danielle; Bezzerides, Vassilios; Guatimosim, Silvia; Guo, Yuxuan; Gu, Fei; Zhou, Pingzhu; Lin, Zhiqiang; Ma, Qing; Liu, Jianming; Wang, Da-Zhi; Pu, William T

2018-01-05

Although mitochondrial diseases often cause abnormal myocardial development, the mechanisms by which mitochondria influence heart growth and function are poorly understood. To investigate these disease mechanisms, we studied a genetic model of mitochondrial dysfunction caused by inactivation of Tfam (transcription factor A, mitochondrial), a nuclear-encoded gene that is essential for mitochondrial gene transcription and mitochondrial DNA replication. Tfam inactivation by Nkx2.5 Cre caused mitochondrial dysfunction and embryonic lethal myocardial hypoplasia. Tfam inactivation was accompanied by elevated production of reactive oxygen species (ROS) and reduced cardiomyocyte proliferation. Mosaic embryonic Tfam inactivation confirmed that the block to cardiomyocyte proliferation was cell autonomous. Transcriptional profiling by RNA-seq demonstrated the activation of the DNA damage pathway. Pharmacological inhibition of ROS or the DNA damage response pathway restored cardiomyocyte proliferation in cultured fetal cardiomyocytes. Neonatal Tfam inactivation by AAV9-cTnT-Cre caused progressive, lethal dilated cardiomyopathy. Remarkably, postnatal Tfam inactivation and disruption of mitochondrial function did not impair cardiomyocyte maturation. Rather, it elevated ROS production, activated the DNA damage response pathway, and decreased cardiomyocyte proliferation. We identified a transient window during the first postnatal week when inhibition of ROS or the DNA damage response pathway ameliorated the detrimental effect of Tfam inactivation. Mitochondrial dysfunction caused by Tfam inactivation induced ROS production, activated the DNA damage response, and caused cardiomyocyte cell cycle arrest, ultimately resulting in lethal cardiomyopathy. Normal mitochondrial function was not required for cardiomyocyte maturation. Pharmacological inhibition of ROS or DNA damage response pathways is a potential strategy to prevent cardiac dysfunction caused by some forms of mitochondrial dysfunction. © 2017 American Heart Association, Inc.

Executive functions and social cognition in highly lethal self-injuring patients with borderline personality disorder.

PubMed

Williams, Gregory E; Daros, Alexander R; Graves, Bryanna; McMain, Shelley F; Links, Paul S; Ruocco, Anthony C

2015-04-01

Risk for potentially lethal self-injurious behavior in borderline personality disorder (BPD) may be associated with deficits in neuropsychological functions and social cognition. In particular, individuals with BPD engaging in more medically damaging self-injurious behaviors may have more severe executive function deficits and altered emotion perception as compared to patients engaging in less lethal acts. In the current study, 58 patients with BPD reporting a lifetime history of self-injurious behavior were administered neuropsychological measures of response inhibition, planning and problem-solving,and tests of facial emotion recognition and discrimination. Patients who engaged in more medically lethal self-injurious behaviors reported engaging in impulsive behaviors more frequently and displayed neuropsychological deficits in problem-solving and response inhibition. They were also less accurate in recognizing happy facial expressions and in discerning subtle differences in emotional intensity in sad facial expressions. These findings suggest that patients with BPD that engage in more physically damaging self-injurious behaviors may have greater difficulties with behavioral control and employ less efficient problem-solving strategies. Problems in facial emotion recognition and discrimination may contribute to interpersonal difficulties in patients with BPD who self-injure. (c) 2015 APA, all rights reserved).

Progression of pectinate ligament dysplasia over time in two populations of Flat-Coated Retrievers.

PubMed

Pearl, Rose; Gould, David; Spiess, Bernhard

2015-01-01

Two of the authors (DG, BS) independently observed that a number of Flat-Coated Retrievers (FCRs) previously unaffected by pectinate ligament dysplasia (PLD) appeared to develop the condition later in life. This study was instigated to investigate progression of PLD within individual dogs over time. Flat-Coated Retrievers that had previously undergone gonioscopy under the UK/ECVO hereditary eye schemes were included in the study. A second gonioscopic examination was performed 1.92-12.58 years later (mean 6, median 5.75 years) and the results compared. 39 FCR (17 males, 22 females) in the UK and 57 FCR (27 males, 30 females) in Switzerland were included. Slit-lamp biomicroscopy, indirect ophthalmoscopy, and gonioscopy were performed in all dogs. Gonioscopy allowed classification as either unaffected or affected; percentage of the iridocorneal drainage angle (ICA) affected by PLD was determined, before calculating progression observed as mild, moderate, or severe. 39 of 96 (40.6%) dogs demonstrated progression of PLD (P < 0.0001). Of these, 13 of 96 (13.5%) were classified as mild progression (from either unaffected to 10-20% or 10-20% to 20-90% ICA affected). Progression was more extensive in 26 of 96 (27.1%) dogs (P < 0.0001), of which 12 of 96 (12.5%) went from unaffected to severe PLD of >90% ICA affected, consistent with a high risk of glaucoma. To the authors' knowledge, this is the first report describing progression of PLD in individual dogs over time, in a breed affected by primary, angle closure glaucoma. © 2013 American College of Veterinary Ophthalmologists.

Engineering of pulsed laser deposited calcium phosphate biomaterials in controlled atmospheres

NASA Astrophysics Data System (ADS)

Drukteinis, Saulius E.

Synthetic calcium phosphates (CAP) such as hydroxyapatite (HA) have been used as regenerative bone graft materials and also as thin films to improve the integration of biomedical implant devices within skeletal tissue. Pulsed laser deposition (PLD) can deposit crystalline HA with significant adhesion on titanium biomaterials. However, there are PLD processing constraints due to the complex physical and chemical interactions occurring simultaneously during PLD, which influence ablation plume formation and development. In this investigation PLD CAP films were engineered with a focus on novel decoupling of partial pressure of H2O (g) ( PH2O ) from total background pressure, in combination with substrate heat treatment and laser energy density control. Characterization of these films was performed with X-ray Diffraction, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Fourier Transform Infrared Spectroscopy, and Optical Profilometry. In vitro cellular adhesion testing was also performed using osteoblast (MC3T3) cell lines to evaluate adhesion of bone-forming cells on processed PLD CAP samples. Preferred a-axis orientation films were deposited in H2O (g) saturated atmospheres with reduced laser fluence (< 4 J/cm2). Crystalline HA/tetracalcium phosphate (TTCP) films were deposited in H2O ( g)-deficient atmospheres with higher laser fluence (> 3 J/cm 2). Varied PH2O resulted in control of biphasic HA/TTCP composition with increasing TTCP at lower PH2O . These were dense continuous films composed of micron-scale particles. Cellular adhesion assays did not demonstrate a significant difference between osteoblast adhesion density on HA films compared with biphasic HA/TTCP films. Room temperature PLD at varied PH2O combined with furnace heat treatment resulted in controlled variation in surface amplitude parameters including surface roughness (S a), root mean square (Sq), peak to valley height (St), and ten-point height ( Sz). These discontinuous films were composed of nano-scale particles and resulted in significant osteoblast adhesion compared to control samples or to PLD CAP films deposited on heated substrates. Surface amplitude parameters (Sa, Sq, St, and Sz) correlated with osteoblast adhesion. This new approach of control over H2O ( g) operating atmospheres enabled the deposition of unique PLD CAP films with potential use as thin films for biomedical implants or as regenerative bone graft materials. Keywords: hydroxyapatite, pulsed laser deposition, biomaterials.

Disease severity in a mouse model of ataxia telangiectasia is modulated by the DNA damage checkpoint gene Hus1

PubMed Central

Balmus, Gabriel; Zhu, Min; Mukherjee, Sucheta; Lyndaker, Amy M.; Hume, Kelly R.; Lee, Jaesung; Riccio, Mark L.; Reeves, Anthony P.; Sutter, Nathan B.; Noden, Drew M.; Peters, Rachel M.; Weiss, Robert S.

2012-01-01

The human genomic instability syndrome ataxia telangiectasia (A-T), caused by mutations in the gene encoding the DNA damage checkpoint kinase ATM, is characterized by multisystem defects including neurodegeneration, immunodeficiency and increased cancer predisposition. ATM is central to a pathway that responds to double-strand DNA breaks, whereas the related kinase ATR leads a parallel signaling cascade that is activated by replication stress. To dissect the physiological relationship between the ATM and ATR pathways, we generated mice defective for both. Because complete ATR pathway inactivation causes embryonic lethality, we weakened the ATR mechanism to different degrees by impairing HUS1, a member of the 911 complex that is required for efficient ATR signaling. Notably, simultaneous ATM and HUS1 defects caused synthetic lethality. Atm/Hus1 double-mutant embryos showed widespread apoptosis and died mid-gestationally. Despite the underlying DNA damage checkpoint defects, increased DNA damage signaling was observed, as evidenced by H2AX phosphorylation and p53 accumulation. A less severe Hus1 defect together with Atm loss resulted in partial embryonic lethality, with the surviving double-mutant mice showing synergistic increases in genomic instability and specific developmental defects, including dwarfism, craniofacial abnormalities and brachymesophalangy, phenotypes that are observed in several human genomic instability disorders. In addition to identifying tissue-specific consequences of checkpoint dysfunction, these data highlight a robust, cooperative configuration for the mammalian DNA damage response network and further suggest HUS1 and related genes in the ATR pathway as candidate modifiers of disease severity in A-T patients. PMID:22575700

Damage control surgery in the abdomen: an approach for the management of severe injured patients.

PubMed

Germanos, Stylianos; Gourgiotis, Stavros; Villias, Constantinos; Bertucci, Marco; Dimopoulos, Nikitas; Salemis, Nikolaos

2008-06-01

Damage control is well established as a potentially life-saving procedure in a few selected critically injured patients. In these patients the 'lethal triad' of hypothermia, acidosis, and coagulopathy is presented as a vicious cycle that often can not be interrupted and which marks the limit of the patient's ability to cope with the physiological consequences of injury. The principles of damage control have led to improved survival and to stopped bleeding until the physiologic derangement has been restored and the patient could undergo a prolong operation for definitive repair. Although morbidity is remaining high, it is acceptable if it comes in exchange for improved survival. There are five critical decision-making stages of damage control: I, patient selection and decision to perform damage control; II, operation and intraoperative reassessment of laparotomy; III, resuscitation in the intensive care unit; IV, definitive procedures after returning to the operating room; and V, abdominal wall reconstruction. The purpose of this article is to review the physiology of the components of the 'lethal triad', the indication and principles of abdominal damage control of trauma patients, the reoperation time, and the pathophysiology of abdominal compartment syndrome.

Identification of a new phospholipase D in Carica papaya latex.

PubMed

Abdelkafi, Slim; Abousalham, Abdelkarim; Fendri, Imen; Ogata, Hiroyuki; Barouh, Nathalie; Fouquet, Benjamin; Scheirlinckx, Frantz; Villeneuve, Pierre; Carrière, Frédéric

2012-05-15

Phospholipase D (PLD) is a lipolytic enzyme involved in signal transduction, vesicle trafficking and membrane metabolism. It catalyzes the hydrolysis and transphosphatidylation of glycerophospholipids at the terminal phosphodiester bond. The presence of a PLD in the latex of Carica papaya (CpPLD1) was demonstrated by transphosphatidylation of phosphatidylcholine (PtdCho) in the presence of 2% ethanol. Although the protein could not be purified to homogeneity due to its presence in high molecular mass aggregates, a protein band was separated by SDS-PAGE after SDS/chloroform-methanol/TCA-acetone extraction of the latex insoluble fraction. This material was digested with trypsin and the amino acid sequences of the tryptic peptides were determined by micro-LC/ESI/MS/MS. These sequences were used to identify a partial cDNA (723 bp) from expressed sequence tags (ESTs) of C. papaya. Based upon EST sequences, a full-length gene was identified in the genome of C. papaya, with an open reading frame of 2424 bp encoding a protein of 808 amino acid residues, with a theoretical molecular mass of 92.05 kDa. From sequence analysis, CpPLD1 was identified as a PLD belonging to the plant phosphatidylcholine phosphatidohydrolase family. Copyright © 2012 Elsevier B.V. All rights reserved.

Differential Expression of Ccn4 and Other Genes Between Metastatic and Non-metastatic EL4 Mouse Lymphoma Cells.

PubMed

Chahal, Manpreet S; Ku, H Teresa; Zhang, Zhihong; Legaspi, Christian M; Luo, Angela; Hopkins, Mandi M; Meier, Kathryn E

Previous work characterized variants of the EL4 murine lymphoma cell line. Some are non-metastatic, and others metastatic, in syngenic mice. In addition, metastatic EL4 cells were stably transfected with phospholipase D2 (PLD2), which further enhanced metastasis. Microarray analyses of mRNA expression was performed for non-metastatic, metastatic, and PLD2-expressing metastatic EL4 cells. Many differences were observed between non-metastatic and metastatic cell lines. One of the most striking new findings was up-regulation of mRNA for the matricellular protein WNT1-inducible signaling pathway protein 1 (CCN4) in metastatic cells; increased protein expression was verified by immunoblotting and immunocytochemistry. Other differentially expressed genes included those for reproductive homeobox 5 (Rhox5; increased in metastatic) and cystatin 7 (Cst7; decreased in metastatic). Differences between PLD2-expressing and parental cell lines were limited but included the signaling proteins Ras guanyl releasing protein 1 (RGS18; increased with PLD2) and suppressor of cytokine signaling 2 (SOCS2; decreased with PLD2). The results provide insights into signaling pathways potentially involved in conferring metastatic ability on lymphoma cells. Copyright© 2016, International Institute of Anticancer Research (Dr. John G. Delinasios), All rights reserved.

Self-report and long-term field measures of MP3 player use: how accurate is self-report?

PubMed

Portnuff, C D F; Fligor, B J; Arehart, K H

2013-02-01

This study was designed to evaluate the usage patterns of portable listening device (PLD) listeners, and the relationships between self-report measures and long-term dosimetry measures of listening habits. This study used a descriptive correlational design. Participants (N = 52) were 18-29 year old men and women who completed surveys. A randomly assigned subset (N = 24) of participants had their listening monitored by dosimetry for one week. Median weekly noise doses reported and measured through dosimetry were low (9-93%), but 14.3% of participants reported exceeding a 100% noise dose weekly. When measured by dosimetry, 16.7% of participants exceeded a 100% noise dose weekly. The self-report question that best predicted the dosimetry-measured dose asked participants to report listening duration and usual listening level on a visual-analog scale. This study reports a novel dosimetry system that can provide accurate measures of PLD use over time. When not feasible, though, the self-report question described could provide a useful research or clinical tool to estimate exposure from PLD use. Among the participants in this study, a small but substantial percentage of PLD users incurred exposure from PLD use alone that increases their risk of music-induced hearing loss.

Evidence for a Lithic Unit Within the North Polar Layered Deposits

NASA Astrophysics Data System (ADS)

Horgan, B.; Smith, I.; Seelos, F.

2016-09-01

Orbital spectra suggest that sediments on Planum Boreum are pyroxene-bearing, and the source unit for these "veneers" may be associated with a radar reflection within the PLD. A lithic unit within the PLD may have influenced their thermal stability.

PARP inhibition as a prototype for synthetic lethal screens.

PubMed

Liu, Xuesong

2013-01-01

Although DNA damaging chemotherapy and radiation therapy remain the main stay of current treatments for cancer patient, these therapies usually have toxic side effect and narrow therapeutic window. One of the challenges in cancer drug discovery is how to identify drugs that selectively kill cancer cells while leaving the normal cell intact. Recently, synthetic lethality has been applied to cancer drug discovery in various settings, and has become a promising approach for identifying novel agents for the treatment of cancer. A prototypical example is the synthetic lethal interaction between PARP inhibition and BRCA deficiency. PARP inhibitors represent the most advanced clinical agents targeting specifically DNA repair mechanisms in cancer therapy. In this chapter, I will review the molecular mechanism for this synthetic lethality and the clinical applications for PARP inhibitors. I will also discuss the formats of synthetic lethal screens, current progress on the utilization of these screens, and some of the advantages and challenges of synthetic lethal screens in cancer drug discovery.

Deletion of a dynamic surface loop improves stability and changes kinetic behavior of phosphatidylinositol-synthesizing Streptomyces phospholipase D.

PubMed

Damnjanović, Jasmina; Nakano, Hideo; Iwasaki, Yugo

2014-04-01

Supplementary phosphatidylinositol (PI) was shown to improve lipid metabolism in animals, thus it is interesting for pharmaceutical and nutritional applications. Homogenous PI can be produced in transphosphatidylation of phosphatidylcholine (PC) with myo-inositol catalyzed by phospholipase D (PLD). Only bacterial enzymes able to catalyze PI synthesis are Streptomyces antibioticus PLD (SaPLD) variants, among which DYR (W187D/Y191Y/Y385R) has the best kinetic profile. Increase in PI yield is possible by providing excess of solvated myo-inositol, which is achievable at high temperatures due to its highly temperature-dependent solubility. However, high-temperature PI synthesis requires the thermostable PLD. Previous site-directed combinatorial mutagenesis at the residues of DYR having high B-factor yielded the most improved variant, D40H/T291Y DYR, obtained by the combination of two selected mutations. D40 and T291 are located within dynamic surface loops, D37-G45 (termed D40 loop) and G273-T313. Thus, in this work, thermostabilization of DYR SaPLD was attempted by rational design based on deletion of the D40 loop, generating two variants, Δ37-45 DYR and Δ38-46 DYR PLD. Δ38-46 DYR showed highest thermostability as its activity half-life at 70°C proved 11.7 and 8.0 times longer than that of the DYR and Δ37-45 DYR, respectively. Studies on molecular dynamics predicted Δ38-46 DYR to have the least average RMSD change as temperature dramatically increases. At 60 and 70°C, both mutants synthesized PI in a twofold higher yield compared to the DYR, while at the same time produced less of the hydrolytic side-product, phosphatidic acid. © 2013 Wiley Periodicals, Inc.

Adaptive response in animals exposed to non-ionizing radiofrequency fields: some underlying mechanisms.

PubMed

Cao, Yi; Tong, Jian

2014-04-22

During the last few years, our research group has been investigating the phenomenon of adaptive response in animals exposed to non-ionizing radiofrequency fields. The results from several separate studies indicated a significant increase in survival, decreases in genetic damage as well as oxidative damage and, alterations in several cellular processes in mice pre-exposed to radiofrequency fields and subsequently subjected to sub-lethal or lethal doses of γ-radiation or injected with bleomycin, a radiomimetic chemical mutagen. These observations indicated the induction of adaptive response providing the animals the ability to resist subsequent damage. Similar studies conducted by independent researchers in mice and rats have supported our observation on increased survival. In this paper, we have presented a brief review of all of our own and other independent investigations on radiofrequency fields-induced adaptive response and some underlying mechanisms discussed.

Adaptive Response in Animals Exposed to Non-Ionizing Radiofrequency Fields: Some Underlying Mechanisms

PubMed Central

Cao, Yi; Tong, Jian

2014-01-01

During the last few years, our research group has been investigating the phenomenon of adaptive response in animals exposed to non-ionizing radiofrequency fields. The results from several separate studies indicated a significant increase in survival, decreases in genetic damage as well as oxidative damage and, alterations in several cellular processes in mice pre-exposed to radiofrequency fields and subsequently subjected to sub-lethal or lethal doses of γ-radiation or injected with bleomycin, a radiomimetic chemical mutagen. These observations indicated the induction of adaptive response providing the animals the ability to resist subsequent damage. Similar studies conducted by independent researchers in mice and rats have supported our observation on increased survival. In this paper, we have presented a brief review of all of our own and other independent investigations on radiofrequency fields-induced adaptive response and some underlying mechanisms discussed. PMID:24758897

Viral single-strand DNA induces p53-dependent apoptosis in human embryonic stem cells.

PubMed

Hirsch, Matthew L; Fagan, B Matthew; Dumitru, Raluca; Bower, Jacquelyn J; Yadav, Swati; Porteus, Matthew H; Pevny, Larysa H; Samulski, R Jude

2011-01-01

Human embryonic stem cells (hESCs) are primed for rapid apoptosis following mild forms of genotoxic stress. A natural form of such cellular stress occurs in response to recombinant adeno-associated virus (rAAV) single-strand DNA genomes, which exploit the host DNA damage response for replication and genome persistence. Herein, we discovered a unique DNA damage response induced by rAAV transduction specific to pluripotent hESCs. Within hours following rAAV transduction, host DNA damage signaling was elicited as measured by increased gamma-H2AX, ser15-p53 phosphorylation, and subsequent p53-dependent transcriptional activation. Nucleotide incorporation assays demonstrated that rAAV transduced cells accumulated in early S-phase followed by the induction of apoptosis. This lethal signaling sequalae required p53 in a manner independent of transcriptional induction of Puma, Bax and Bcl-2 and was not evident in cells differentiated towards a neural lineage. Consistent with a lethal DNA damage response induced upon rAAV transduction of hESCs, empty AAV protein capsids demonstrated no toxicity. In contrast, DNA microinjections demonstrated that the minimal AAV origin of replication and, in particular, a 40 nucleotide G-rich tetrad repeat sequence, was sufficient for hESC apoptosis. Our data support a model in which rAAV transduction of hESCs induces a p53-dependent lethal response that is elicited by a telomeric sequence within the AAV origin of replication.

Targeting the DNA damage response in oncology: past, present and future perspectives.

PubMed

Basu, Bristi; Yap, Timothy A; Molife, L Rhoda; de Bono, Johann S

2012-05-01

The success of poly(ADP-ribose) polymerase inhibition in BRCA1 or BRCA2 deficient tumors as an anticancer strategy provided proof-of-concept for a synthetic lethality approach in oncology. There is therefore now active interest in expanding this approach to include other agents targeting the DNA damage response (DDR). We review lessons learnt from the development of inhibitors against DNA damage response mechanisms and envision the future of DNA repair inhibition in oncology. Preclinical synthetic lethality screens may potentially identify the best combinations of DNA-damaging drugs with inhibitors of DNA repair and the DDR or two agents acting within the DDR. Efforts are currently being made to establish robust and cost-effective assays that may be implemented within appropriate time-scales in parallel with future clinical studies. Detection of relevant mutations in a high-throughput manner, such as with next-generation sequencing for genes implicated in homologous recombination, including BRCA1, BRCA2, and ataxia telangiectasia mutated is anticipated. Novel approaches targeting the DDR are currently being evaluated and inhibitors of ATM, RAD51 and DNA-dependent protein kinase are now in early drug discovery and development. There remains great enthusiasm in oncology practice for pursuing the strategy of synthetic lethality. The future development of antitumor agents targeting the DDR should include detailed correlative biomarker work within early phase clinical studies wherever possible, with clear attempts to identify doses at which robust target modulation is observed.

Portable music player users: cultural differences and potential dangers.

PubMed

Levey, Sandra; Fligor, Brian J; Cutler, Cecelia; Harushimana, Immaculee

2013-01-01

Many studies have examined the use of portable music players portable listening devices (PLDs) from various ethnic groups. Some findings suggest that there may be differences among ethnic groups that lead to louder or longer listening when using PLD devices. For example, some studies found that Hispanic PLD users listen at higher volume levels while other studies found that African American PLD users listen at higher volume levels. No investigator has explained the reasons for differences among ethnic groups in listening intensity. This paper will address the possible reasons for these differences and offer guidelines for the prevention of noise-induced hearing loss.

Inhibition of BRCA2 and Thymidylate Synthase Creates Multidrug Sensitive Tumor Cells via the Induction of Combined "Complementary Lethality".

PubMed

Rytelewski, Mateusz; Ferguson, Peter J; Maleki Vareki, Saman; Figueredo, Rene; Vincent, Mark; Koropatnick, James

2013-03-12

A high mutation rate leading to tumor cell heterogeneity is a driver of malignancy in human cancers. Paradoxically, however, genomic instability can also render tumors vulnerable to therapeutic attack. Thus, targeting DNA repair may induce an intolerable level of DNA damage in tumor cells. BRCA2 mediates homologous recombination repair, and BRCA2 polymorphisms increase cancer risk. However, tumors with BRCA2 mutations respond better to chemotherapy and are associated with improved patient prognosis. Thymidylate synthase (TS) is also involved in DNA maintenance and generates cellular thymidylate. We determined that antisense downregulation of BRCA2 synergistically potentiated drugs with mechanisms of action related to BRCA2 function (cisplatin, melphalan), a phenomenon we named "complementary lethality." TS knockdown induced complementary lethality to TS-targeting drugs (5-FUdR and pemetrexed) but not DNA cross-linking agents. Combined targeting of BRCA2 and TS induced complementary lethality to both DNA-damaging and TS-targeting agents, thus creating multidrug sensitive tumors. In addition, we demonstrated for the first time that simultaneous downregulation of both targets induced combined complementary lethality to multiple mechanistically different drugs in the same cell population. In this study, we propose and define the concept of "complementary lethality" and show that actively targeting BRCA2 and TS is of potential therapeutic benefit in multidrug treatment of human tumors. This work has contributed to the development of a BRCA2-targeting antisense oligdeoxynucleotide (ASO) "BR-1" which we will test in vivo in combination with our TS-targeting ASO "SARI 83" and attempt early clinical trials in the future.Molecular Therapy - Nucleic Acids (2013) 2, e78; doi:10.1038/mtna.2013.7 published online 12 March 2013.

Reinventing Professional Learning and Development: Ensuring Relevance and Building Resilience

ERIC Educational Resources Information Center

Owen, Hazel

2012-01-01

Innovation may best be considered as reinvention rather than invention. This observation is supported by a gradually accelerating change in "how" professional learning and development (PLD) for education practitioners and leaders is being offered, designed, facilitated, and evaluated. The reinvention of PLD includes shifts towards…

Radiochromatographic assay of N-acyl-phosphatidylethanolamine-specific phospholipase D activity.

PubMed

Fezza, Filomena; Gasperi, Valeria; Mazzei, Cinzia; Maccarrone, Mauro

2005-04-01

A radiochromatographic method has been set up to assay the activity of N-acyl-phosphatidylethanolamine-specific phospholipase D (NAPE-PLD), based on reversed-phase high-performance liquid chromatography (HPLC) and online scintillation counting. The anandamide (N-arachidonoylethanolamine, AEA), product released by NAPE-PLD from the N-arachidonoyl-phosphatidylethanolamine (NArPE) substrate, was separated using a C18 column eluted with methanol-water-acetic acid and was quantified with an external standard method. Baseline separation of AEA and NArPE was completed in less than 15 min, with a detection limit of 0.5 fmol AEA at a signal-to-noise ratio of 4:1. The sensitivity and accuracy of the radiochromatographic procedure allowed detection and characterization of NAPE-PLD activity in very tiny tissue samples or in samples where the enzymatic activity is very low. With this method, we could determine the kinetic constants (i.e., apparent Michaelis-Menten constant (Km) of 40.0+/-5.6 microM and maximum velocity (Vmax) of 22.2+/-3.5 pmol/min per milligram protein toward NArPE) and the distribution of NAPE-PLD activity in brain areas and peripheral tissues of mouse. In addition, we could collect unprecedented evidence that compounds widely used in studies of the endocannabinoid system (e.g., AEA and congeners, receptor a(nta)gonists and inhibitors of AEA degradation) can also affect NAPE-PLD activity.

HPV-16 E7 expression up-regulates phospholipase D activity and promotes rapamycin resistance in a pRB-dependent manner.

PubMed

Rabachini, Tatiana; Boccardo, Enrique; Andrade, Rubiana; Perez, Katia Regina; Nonogaki, Suely; Cuccovia, Iolanda Midea; Villa, Luisa Lina

2018-04-27

Human Papillomavirus (HPV) infection is the main risk factor for the development and progression of cervical cancer. HPV-16 E6 and E7 expression is essential for induction and maintenance of the transformed phenotype. These oncoproteins interfere with the function of several intracellular proteins, including those controlling the PI3K/AKT/mTOR pathway in which Phospolipase D (PLD) and Phosphatidic acid (PA) play a critical role. PLD activity was measured in primary human keratinocytes transduced with retroviruses expressing HPV-16 E6, E7 or E7 mutants. The cytostatic effect of rapamycin, a well-known mTOR inhibitor with potential clinical applications, was evaluated in monolayer and organotypic cultures. HPV-16 E7 expression in primary human keratinocytes leads to an increase in PLD expression and activity. Moreover, this activation is dependent on the ability of HPV-16 E7 to induce retinoblastoma protein (pRb) degradation. We also show that cells expressing HPV-16 E7 or silenced for pRb acquire resistance to the antiproliferative effect of rapamycin. This is the first indication that HPV oncoproteins can affect PLD activity. Since PA can interfere with the ability of rapamycin to bind mTOR, the use of combined strategies to target mTOR and PLD activity might be considered to treat HPV-related malignancies.

The effect of hyperthermia on the radiation response of crypt cells in mouse jejunum

NASA Technical Reports Server (NTRS)

Wilson, J. D.

1978-01-01

The effect of hyperthermia and/or gamma-radiation on the survival of intestinal crypt cells was studied in BDF sub 1 mice using a microcolony assay. Hyperthermia treatments, which in themselves caused no detectable cell lethality, inhibited the capacity of crypt cells to repair sublethal radiation damage. In addition, heat applied either before or after single radiation exposures potentiated lethal damage to crypt cells; the degree of enhancement was dependent on the time interval between treatments. At the levels of heating employed, DNA synthesis in the intestinal epithelium was significantly reduced immediately following exposure, but returned rapidly to normal levels. No further disturbances in cellular kinetics were observed for up to 10 days after heating.

Expression of the cloned ColE1 kil gene in normal and Kilr Escherichia coli.

PubMed Central

Altieri, M; Suit, J L; Fan, M L; Luria, S E

1986-01-01

The kil gene of the ColE1 plasmid was cloned under control of the lac promoter. Its expression under this promoter gave rise to the same pattern of bacterial cell damage and lethality as that which accompanies induction of the kil gene in the colicin operon by mitomycin C. This confirms that cell damage after induction is solely due to expression of kil and is independent of the cea or imm gene products. Escherichia coli derivatives resistant to the lethal effects of kil gene expression under either the normal or the lac promoter were isolated and found to fall into several classes, some of which were altered in sensitivity to agents that affect the bacterial envelope. PMID:2946661

SCHISTOSOMIASIS: AGE OF SNAILS AND SUSCEPTIBILITY TO X-IRRADIATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szumlewicz, A.P.

1964-04-17

Studies on sensitivity of Australorbis glabratus to x rays have defined the chronological and physiological age at which the snail is most sensitive to radiation damage. Results showed that the dose producing 50-percent mortality at 30 days after irradiation increased with age but that at 90 days it was practically constant from 2 to 210 days of age. In view of the avaiIable data on recovery from radiation damage caused by doses from 6000 to 9000 roentgens it is suggested that doses above those causing 50% lethality at 60 days but below those causing 50% lethality for 30 days shouldmore » be considered in setting up radiation barriers to cortrol snails in water-distribution systems. (auth)« less

NORF5/HUG1 is a component of the MEC1-mediated checkpoint response to DNA damage and replication arrest in Saccharomyces cerevisiae.

PubMed

Basrai, M A; Velculescu, V E; Kinzler, K W; Hieter, P

1999-10-01

Analysis of global gene expression in Saccharomyces cerevisiae by the serial analysis of gene expression technique has permitted the identification of at least 302 previously unidentified transcripts from nonannotated open reading frames (NORFs). Transcription of one of these, NORF5/HUG1 (hydroxyurea and UV and gamma radiation induced), is induced by DNA damage, and this induction requires MEC1, a homolog of the ataxia telangiectasia mutated (ATM) gene. DNA damage-specific induction of HUG1, which is independent of the cell cycle stage, is due to the alleviation of repression by the Crt1p-Ssn6p-Tup1p complex. Overexpression of HUG1 is lethal in combination with a mec1 mutation in the presence of DNA damage or replication arrest, whereas a deletion of HUG1 rescues the lethality due to a mec1 null allele. HUG1 is the first example of a NORF with important biological functional properties and defines a novel component of the MEC1 checkpoint pathway.

Hybrid laser technology and doped biomaterials

NASA Astrophysics Data System (ADS)

Jelínek, Miroslav; Zemek, Josef; Remsa, Jan; Mikšovský, Jan; Kocourek, Tomáš; Písařík, Petr; Trávníčková, Martina; Filová, Elena; Bačáková, Lucie

2017-09-01

Hybrid laser-based technologies for deposition of new types of doped thin films are presented. The focus is on arrangements combining pulsed laser deposition (PLD) with magnetron sputtering (MS), and on the setup with two simultaneously running PLD systems (dual PLD). Advantages and disadvantages of both arrangements are discussed. Layers of different dopants concentration were prepared. Experience with deposition of chromium and titanium doped diamond-like carbon (DLC) films for potential coating of bone implants is presented. Properties of the layers prepared by both technologies are compared and discussed. The suitability of the layers for colonization with human bone marrow mesenchymal stem cells and human osteoblast-like cells, were also evaluated under in vitro conditions.

[Mutagenic and antimutagenic properties of bemitil].

PubMed

Seredenin, S B; Bobkov, Iu G; Durnev, A D; Dubovskaia, O Iu

1986-07-01

Complex research of the genetic activity of a new 2-mercaptobenzimidazole derivative bemythyl has shown that the drug failed to induce recessive, age-related lethal mutations in drosophila, dominant lethal mutations in germ mammalian cells and chromosomal damage in murine bone marrow cells and human peripheral blood cell cultures. The experiments on mice have demonstrated that therapeutic bemythyl doses caused a two-fold decrease in the level of aberrant cells induced by alkylating agents--fotrin and fopurin.

Stable gastric pentadecapeptide BPC 157 in trials for inflammatory bowel disease (PL-10, PLD-116, PL14736, Pliva, Croatia) heals ileoileal anastomosis in the rat.

PubMed

Vuksic, Tihomir; Zoricic, Ivan; Brcic, Luka; Sever, Marko; Klicek, Robert; Radic, Bozo; Cesarec, Vedran; Berkopic, Lidija; Keller, Neike; Blagaic, Alenka Boban; Kokic, Neven; Jelic, Ivan; Geber, Juraj; Anic, Tomislav; Seiwerth, Sven; Sikiric, Predrag

2007-01-01

Gastric pentadecapeptide BPC 157 (BPC 157), which has been shown to be safe in clinical trials for inflammatory bowel disease (PL-10, PLD-116, PL14736, Pliva, Croatia), may be able to cure intestinal anastomosis dehiscence. This antiulcer peptide shows no toxicity, is limit test negative, and a lethal dose is not achieved. It is stable in human gastric juice. In comparison with other standard treatments it is more effective for ulcers and various wounds, and can be used without a carrier needed for other peptides, both locally and systemically (i.e., perorally, parenterally). We studied the effectiveness of BPC 157 for ileoileal anastomosis healing in rats. We assessed ileoileal anastomosis dehiscence macroscopically, histologically, and biomechanically (volume [ml] infused through a syringe-perfusion pump system (1 ml/10 s), and pressure [mmHg] to leak induction [catheter connected to a chamber and a monitor, at 10 cm proximal to anastomosis]), at 1, 2, 3, 4, 5, 6, 7, and 14 days. BPC 157 (10 microg, 10 ng, 10 pg/kg i.p. (or saline [5 ml/kg]) was first administered after surgery, while it was last given 24 h before either assessment or sacrifice. Throughout the experiment, both higher doses of BPC 157 were shown to improve all parameters of anastomotic wound healing. The formation of adhesions remained slight, the blood vessels were filled with blood, and a mild intestinal passage obstruction was only temporarily observed. Anastomosis without leakage induces markedly higher volume and pressure values, with a continuous increase toward healthy values. From day 1, edema was markedly attenuated and the number of granulocytes decreased, while from days 4 or 5 necrosis decreased and granulation tissue, reticulin, and collagen formation substantially increased, thus resulting in increased epithelization. This study showed BPC 157 to have a beneficial effect on ileoileal anastomosis healing in the rat.

Putting the PLE into PLD: Virtual Professional Learning and Development

ERIC Educational Resources Information Center

Owen, Hazel

2014-01-01

The range of affordances that a virtual environment offers can provide opportunities for more formal Professional Learning and Development (PLD) that has flexibility of choice, time and approach for educators. It was this potential that inspired the design of the Virtual Professional Learning and Development (VPLD) program that was instigated in…

High-speed pre-clinical brain imaging using pulsed laser diode based photoacoustic tomography (PLD-PAT) system

NASA Astrophysics Data System (ADS)

Upputuri, Paul Kumar; Pramanik, Manojit

2016-03-01

Photoacoustic tomography (PAT) is a promising biomedical imaging modality for small animal imaging, breast cancer imaging, monitoring of vascularisation, tumor angiogenesis, blood oxygenation, total haemoglobin concentration etc. The existing PAT systems that uses Q-switched Nd:YAG and OPO nanosecond lasers have limitations in clinical applications because they are expensive, non-potable and not suitable for real-time imaging due to their low pulse repetition rate. Low-energy pulsed near-infrared diode laser which are low-cost, compact, and light-weight (<200 grams), can be used as an alternate. In this work, we present a photoacoustic tomography system with a pulsed laser diode (PLD) that can nanosecond pulses with pulse energy 1.3 mJ/pulse at ~803 nm wavelength and 7000 Hz repetition rate. The PLD is integrated inside a single-detector circular scanning geometric system. To verify the high speed imaging capabilities of the PLD-PAT system, we performed in vivo experimental results on small animal brain imaging using this system. The proposed system is portable, low-cost and can provide real-time imaging.

Phospholipase D1 regulates lymphocyte adhesion via upregulation of Rap1 at the plasma membrane.

PubMed

Mor, Adam; Wynne, Joseph P; Ahearn, Ian M; Dustin, Michael L; Du, Guangwei; Philips, Mark R

2009-06-01

Rap1 is a small GTPase that modulates adhesion of T cells by regulating inside-out signaling through LFA-1. The bulk of Rap1 is expressed in a GDP-bound state on intracellular vesicles. Exocytosis of these vesicles delivers Rap1 to the plasma membrane, where it becomes activated. We report here that phospholipase D1 (PLD1) is expressed on the same vesicular compartment in T cells as Rap1 and is translocated to the plasma membrane along with Rap1. Moreover, PLD activity is required for both translocation and activation of Rap1. Increased T-cell adhesion in response to stimulation of the antigen receptor depended on PLD1. C3G, a Rap1 guanine nucleotide exchange factor located in the cytosol of resting cells, translocated to the plasma membranes of stimulated T cells. Our data support a model whereby PLD1 regulates Rap1 activity by controlling exocytosis of a stored, vesicular pool of Rap1 that can be activated by C3G upon delivery to the plasma membrane.

Phospholipase D2 Mediates Survival Signaling through Direct Regulation of Akt in Glioblastoma Cells*♦

PubMed Central

Bruntz, Ronald C.; Taylor, Harry E.; Lindsley, Craig W.; Brown, H. Alex

2014-01-01

The lack of innovative drug targets for glioblastoma multiforme (GBM) limits patient survival to approximately 1 year following diagnosis. The pro-survival kinase Akt provides an ideal target for the treatment of GBM as Akt signaling is frequently activated in this cancer type. However, the central role of Akt in physiological processes limits its potential as a therapeutic target. In this report, we show that the lipid-metabolizing enzyme phospholipase D (PLD) is a novel regulator of Akt in GBM. Studies using a combination of small molecule PLD inhibitors and siRNA knockdowns establish phosphatidic acid, the product of the PLD reaction, as an essential component for the membrane recruitment and activation of Akt. Inhibition of PLD enzymatic activity and subsequent Akt activation decreases GBM cell viability by specifically inhibiting autophagic flux. We propose a mechanism whereby phosphorylation of beclin1 by Akt prevents binding of Rubicon (RUN domain cysteine-rich domain containing beclin1-interacting protein), an interaction known to inhibit autophagic flux. These findings provide a novel framework through which Akt inhibition can be achieved without directly targeting the kinase. PMID:24257753

INTERACTION OF X AND ULTRAVIOLET RADIATION IN PRODUCTION OF RECESSIVE LETHALS IN DROSOPHILA MELANOGASTER (in Italian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicoletti, B.; Olivieri, G.

1962-01-01

The possibility that uv rays given to different biological systems before or after x rays could modify genetic or cytological effects is reviewed and discussed. Kaufmann and Hollaender's conclusions about the recovering effect of uv rays on chromosomal damage induced in Drosophila sperms by a pre-treatment of x rays are discussed and analyzed taking into accourt some general considerations. Preliminary results of similar experiments on the frequency of sex-linked recessive lethals induced after single and combined x + uv treatments in Drosophila sperms are reported. All our experiments indicate no effect of the uv treatment (at the given wave lengthsmore » and doses) in lowering the frequency of the x-ray-induced recessive lethals. On the contrary, there are some indications for a synergistic action between the two radiations. These results not in agreement with the generally accepted theory that uv rays do recover X-ray- induced chromosomal damages, could be expiained With the well established correlation between chromosomal rejoined breaks and genic mutations. (auth)« less

Inviability of a DNA2 deletion mutant is due to the DNA damage checkpoint.

PubMed

Budd, Martin E; Antoshechkin, Igor A; Reis, Clara; Wold, Barbara J; Campbell, Judith L

2011-05-15

Dna2 is a dual polarity exo/endonuclease, and 5' to 3' DNA helicase involved in Okazaki Fragment Processing (OFP) and Double-Strand Break (DSB) Repair. In yeast, DNA2 is an essential gene, as expected for a DNA replication protein. Suppression of the lethality of dna2Δ mutants has been found to occur by two mechanisms: overexpression of RAD27 (scFEN1) , encoding a 5' to 3' exo/endo nuclease that processes Okazaki fragments (OFs) for ligation, or deletion of PIF1, a 5' to 3' helicase involved in mitochondrial recombination, telomerase inhibition and OFP. Mapping of a novel, spontaneously arising suppressor of dna2Δ now reveals that mutation of rad9 and double mutation of rad9 mrc1 can also suppress the lethality of dna2Δ mutants. Interaction of dna2Δ and DNA damage checkpoint mutations provides insight as to why dna2Δ is lethal but rad27Δ is not, even though evidence shows that Rad27 (ScFEN1) processes most of the Okazaki fragments, while Dna2 processes only a subset.

The proper treatment of language acquisition and change in a population setting.

PubMed

Niyogi, Partha; Berwick, Robert C

2009-06-23

Language acquisition maps linguistic experience, primary linguistic data (PLD), onto linguistic knowledge, a grammar. Classically, computational models of language acquisition assume a single target grammar and one PLD source, the central question being whether the target grammar can be acquired from the PLD. However, real-world learners confront populations with variation, i.e., multiple target grammars and PLDs. Removing this idealization has inspired a new class of population-based language acquisition models. This paper contrasts 2 such models. In the first, iterated learning (IL), each learner receives PLD from one target grammar but different learners can have different targets. In the second, social learning (SL), each learner receives PLD from possibly multiple targets, e.g., from 2 parents. We demonstrate that these 2 models have radically different evolutionary consequences. The IL model is dynamically deficient in 2 key respects. First, the IL model admits only linear dynamics and so cannot describe phase transitions, attested rapid changes in languages over time. Second, the IL model cannot properly describe the stability of languages over time. In contrast, the SL model leads to nonlinear dynamics, bifurcations, and possibly multiple equilibria and so suffices to model both the case of stable language populations, mixtures of more than 1 language, as well as rapid language change. The 2 models also make distinct, empirically testable predictions about language change. Using historical data, we show that the SL model more faithfully replicates the dynamics of the evolution of Middle English.

Directed mutagenesis of the Rickettsia prowazekii pld gene encoding phospholipase D.

PubMed

Driskell, Lonnie O; Yu, Xue-jie; Zhang, Lihong; Liu, Yan; Popov, Vsevolod L; Walker, David H; Tucker, Aimee M; Wood, David O

2009-08-01

Rickettsia prowazekii, the causative agent of epidemic typhus, is an obligately intracytoplasmic bacterium, a lifestyle that imposes significant barriers to genetic manipulation. The key to understanding how this unique bacterium evades host immunity is the mutagenesis of selected genes hypothesized to be involved in virulence. The R. prowazekii pld gene, encoding a protein with phospholipase D activity, has been associated with phagosomal escape. To demonstrate the feasibility of site-directed knockout mutagenesis of rickettsial genes and to generate a nonrevertible vaccine strain, we utilized homologous recombination to generate a pld mutant of the virulent R. prowazekii strain Madrid Evir. Using linear DNA for transformation, a double-crossover event resulted in the replacement of the rickettsial wild-type gene with a partially deleted pld gene. Linear DNA was used to prevent potentially revertible single-crossover events resulting in plasmid insertion. Southern blot and PCR analyses were used to confirm the presence of the desired mutation and to demonstrate clonality. While no phenotypic differences were observed between the mutant and wild-type strains when grown in tissue culture, the pld mutant exhibited attenuated virulence in the guinea pig model. In addition, animals immunized with the mutant strain were protected against subsequent challenge with the virulent Breinl strain, suggesting that this transformant could serve as a nonrevertible, attenuated vaccine strain. This study demonstrates the feasibility of generating site-directed rickettsial gene mutants, providing a new tool for understanding rickettsial biology and furthering advances in the prevention of epidemic typhus.

Large Grooves in the South Polar Layered Deposits: Insights from Spacecraft Data and Terrestrial Analogs

NASA Technical Reports Server (NTRS)

Bridges, N. T.; Herkenhoff, K. E.

2000-01-01

The Martian polar layered deposits (PLD) are probably the best source of information about the recent climate history of Mars, but their origin and the mechanisms of accumulation are still a mystery. The polar layers are sedimentary deposits that most planetary scientists believe are composed of water ice and varying amounts of wind-blown dust, although their composition is poorly constrained. Interpretation of the observed polar stratigraphy in terms of global climate changes is complicated by the significant difference in surface ages between the north and south PLD inferred from crater statistics. The study reported here was undertaken as part of the landing site selection effort for the Mars Polar Lander (MPL) and Deep Space 2 (DS2) missions that made use of all available data. We used Mariner 9, Viking, and Mars Global Surveyor images of the south PLD in the area accessible to MPL and DS2 to evaluate the topography and morphology of grooves, terraced layers, and other features. Here we report on results from grooves that appear to have been carved by strong winds. Because these features are found throughout the interior of the PLD, where MPL and DS2 were targeted to land, their topographic characteristics were judged as important input for landing site safety assessment. The characteristics of the grooves also provide constraints and insights into aeolian processes in the polar regions and the effects these have on PLD ablation. Our results indicate that these grooves do not represent landing hazards at the scale of the images (approx. 80 m/pixel). Their topography and shape do not seem correlated with south PLD layering. No Earth analog of suitable scale exists, although the grooves bear some resemblance to smaller terrestrial deflation hollows found in soft sediment and ice. Additional information is contained in original extended abstract.

One man's poison is another man's meat: using azithromycin-induced phospholipidosis to promote ocular surface health.

PubMed

Liu, Yang; Kam, Wendy R; Ding, Juan; Sullivan, David A

2014-06-05

Drug-induced phospholipidosis (PLD) is a common adverse effect which has led to the termination of clinical trials for many candidate pharmaceuticals. However, this lipid-inducing effect may be beneficial in the treatment of meibomian gland dysfunction (MGD). MGD is the major cause of dry eye disease (DED), which affects 40 million people in the USA and has no cure. Azithromycin (AZM) is a PLD-inducing antibiotic that is used off-label to treat MGD, and is presumably effective because it suppresses the MGD-associated conjunctival inflammation (i.e. posterior blepharitis) and growth of lid bacteria. We hypothesize that AZM can act directly to promote the function of human meibomian gland epithelial cells by inducing PLD in these cells, characterized by the accumulation of lipids and lysosomes. Immortalized human meibomian gland epithelial cells (HMGEC) were cultured with or without azithromycin for 5 days. Cells were evaluated for cholesterol (Filipin) and neutral lipid (LipidTox) staining, as well as the appearance of lysosomes (LysoTracker) and lamellar bodies (transmission electron microscopy, TEM). The lipid composition of cellular lysates was analyzed by high performance thin-layer chromatography. Our findings demonstrate that AZM stimulates the accumulation of free cholesterol, neutral lipids and lysosomes in HMGEC. This AZM-induced increase of neutral lipid content occurred predominantly within lysosomes. Many of these vesicles appeared to be lamellar bodies by TEM, which is the characteristic of PLD. Our findings also show that AZM promotes an accumulation of free and esterified cholesterol, as well as phospholipids in HMGECimmortalized. Our results support our hypothesis and confirm the beneficial effect of PLD induced by AZM on HMGEC. Our discovery reveals a new potential use of PLD-inducing drugs, and makes this adverse effect a beneficial effect. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Reconstructing the energy band electronic structure of pulsed laser deposited CZTS thin films intended for solar cell absorber applications

NASA Astrophysics Data System (ADS)

Pandiyan, Rajesh; Oulad Elhmaidi, Zakaria; Sekkat, Zouheir; Abd-lefdil, Mohammed; El Khakani, My Ali

2017-02-01

We report here on the use of pulsed KrF-laser deposition (PLD) technique for the growth of high-quality Cu2ZnSnS4 (CZTS) thin films onto Si, and glass substrates without resorting to any post sulfurization process. The PLD-CZTS films were deposited at room temperature (RT) and then subjected to post annealing at different temperatures ranging from 200 to 500 °C in Argon atmosphere. The X-ray diffraction and Raman spectroscopy confirmed that the PLD films crystallize in the characteristic kesterite CZTS structure regardless of their annealing temperature (Ta), but their crystallinity is much improved for Ta ≥ 400 °C. The PLD-CZTS films were found to exhibit a relatively dense morphology with a surface roughness (RMS) that increases with Ta (from ∼14 nm at RT to 70 nm at Ta = 500 °C with a value around 40 nm for Ta = 300-400 °C). The optical bandgap of the PLD-CZTS films, was derived from UV-vis transmission spectra analysis, and found to decrease from 1.73 eV for non-annealed films to ∼1.58 eV for those annealed at Ta = 300 °C. These band gap values are very close to the optimum value needed for an ideal solar cell absorber. In order to achieve a complete reconstruction of the one-dimensional energy band structure of these PLD-CZTS absorbers, we have combined both XPS and UPS spectroscopies to determine their chemical bondings, the position of their valence band maximum (relative to Fermi level), and their work function values. This enabled us to sketch out, as accurately as possible, the band alignment of the heterojunction interface formed between CZTS and both CdS and ZnS buffer layer materials.

Survey of the incidence of pectinate ligament dysplasia and glaucoma in the UK Leonberger population.

PubMed

Fricker, Georgina V; Smith, Kerry; Gould, David J

2016-09-01

To determine the prevalence of pectinate ligament dysplasia (PLD) in UK Leonbergers and identify cases affected by glaucoma. Also, to define the spectrum of pectinate ligament (PL) appearance in this breed and determine whether gonioscopic monitoring should be recommended. Data were compiled from 78 prospective gonioscopy examinations performed by one author (GF) and retrospective analysis of 233 UK eye scheme certificates (2009-2014). Clinical cases of glaucoma in Leonbergers diagnosed by UK veterinary ophthalmologists, where gonioscopy of the fellow eyes or histology of affected eyes had been performed, were also reviewed. In the prospective study, intraocular pressure was recorded prior to gonioscopy using a rebound tonometer. Gonioscopy was performed using a slit-lamp biomicroscope with a Koeppe goniolens. PLD was categorized according to the percentage of the iridocorneal drainage angle affected (grade 0 = <25% affected; grade 1 = 25-50% affected; grade 2 = 51-75% affected; and grade 3 = >75% affected), and the degree of narrowing of the angle was noted. Of 78 dogs examined prospectively, 64/78 (82%) were grade 0, 7/78 (9%) were grade 1, 3/78 (4%) were grade 2, and 4/78 (5%) were grade 3. A large phenotypic variation was observed. Spearman's rank correlation showed a positive correlation between age and severity of PLD (P < 0.0055). 52 (22%) of Leonbergers examined under the UK eye scheme 2009-2014 were affected by PLD. Five clinical cases of glaucoma were reviewed where gonioscopy had been performed and one where histology was performed. All individuals had grade 3 PLD with gonioscopy of the contralateral eye or severe goniodysgenesis with histological sections of the affected eye. This survey suggests the prevalence of PLD is sufficient to justify ongoing screening of Leonbergers. © 2015 American College of Veterinary Ophthalmologists.

Oxidative stress in freshwater fish, Labeo rohita as a biomarker of malathion exposure.

PubMed

Patil, Vineetkumar K; David, Muniswamy

2013-12-01

This study examined the effect of lethal (4.5 μg/l) and sublethal (0.45 μg/l) malathion levels on oxidative stress responses of the freshwater edible fish, Labeo rohita. Fish were exposed to lethal (1-4 days) and sublethal (1, 5, 10, and 15 days) periods. In the present study, catalase and protease activity, hydrogen peroxide, malondialdehyde, protein carbonyls, and free amino acids levels increased in the gill, liver, and kidney tissues of fish exposed to lethal and sublethal concentrations of malathion except protein content. Time- and concentration-dependent induction/reduction of the above parameters by lethal and sublethal concentrations of malathion was observed in the tissues (the gill, liver, and kidney) of L. rohita. Thus, the results clearly infer oxidative damage and decline in antioxidant defense due to malathion-induced oxidative stress.

Morphological evolution of nanocrystal metal-on-insulator films grown by pulsed laser deposition

NASA Astrophysics Data System (ADS)

Warrender, Jeffrey Michael

Pulsed laser deposition (PLD) film growth differs from conventional thermal deposition in two essential ways: the depositing species arrive in short bursts of 10--100mus, and with 10--100 eV of kinetic energy. This thesis presents a comprehensive study of the influence of these separate characteristics of the PLD flux on film growth, with the goal of understanding what mechanisms and processes govern PLD morphology evolution. A theoretical description of the early stages of pulsed, non-energetic growth is presented, with the principal results being a discussion of the dimensionless parameters that must be controlled to achieve data collapse for a variety of conditions; the identification of at least four different island size distribution shapes, which characterize the growth mode being observed; and a rate equation formalism for pulsed deposition that gives excellent agreement with results from kinetic Monte Carlo (KMC) simulations. The model system of metal-on-insulator film growth has been studied extensively for thermal deposition, and is known to exhibit a characteristic morphological progression beginning with isolated three-dimensional islands and ending with a percolating, continuous film that conducts electrically. Two separate experimental investigations are reported for PLD growth of this system. In the fast, the details of the PLD pulse are held constant and the pulse frequency is varied; this amounts to varying the time-averaged deposition flux. Non-energetic KMC simulations, which take into account only the pulsed nature of the flux, predicted that, for the case where surface diffusion is very fast compared to the pulse frequency and the deposition rate, percolation thickness would scale with pulse frequency with an exponent of -0.34. Experiments performed at 93°C and 135°C gave scaling exponents of -0.31 and -0.34 respectively, in good agreement with the KMC prediction. The experiments also showed good data collapse when maintaining a constant value B/f, where B is the coalescence "efficiency" and f is the pulse frequency. A separate experimental investigation was performed to compare PLD with thermal deposition under otherwise identical background and substrate conditions; this amounts to studying the effect of varying the average deposition flux. For this case, non-energetic simulations predict that PLD deposits, by virtue of having smaller and more densely spaced islands, would reach percolation with relatively less deposition. (Abstract shortened by UMI.)

Relative biological effectiveness for photons: implication of complex DNA double-strand breaks as critical lesions

NASA Astrophysics Data System (ADS)

Liang, Ying; Fu, Qibin; Wang, Xudong; Liu, Feng; Yang, Gen; Luo, Chunxiong; Ouyang, Qi; Wang, Yugang

2017-03-01

Current knowledge in radiobiology ascribes the adverse biological effects of ionizing radiation primarily to the induction of DNA double-strand breaks (DSBs), which is supposed to be potentially lethal and may be converted to lethal damage due to misrepair. Soft and ultrasoft x-rays have been found to bear elevated biological effectiveness for cell killing compared with conventional x-rays or 60Co γ-rays. This phenomenon is qualitatively interpreted as the increased level of DSB induction for low energy photons, however, a thorough quantitative reasoning is lacking. Here, we systematically compared the relative biological effectiveness (RBE) with relative DSB induction for photons from several hundreds of eV up to MeV. Although there is an approximate two-fold increase in the yields of DSB for low energy photons found in our calculation and a large number of experimental measurements, it is far from enough to account for the three- to four-fold increase in RBE. Further theoretical investigations show that DSB complexity (additional single-strand breaks and base damage within 10 base pairs) increases notably for low energy photons, which largely reconciles the discrepancy between RBE and DSB induction. Our theoretical results are in line with accumulating experimental evidence that complex DSBs are refractory to repair machinery and may contribute predominantly to the formation of lethal damage.

The prevention of benign prostatic hyperplasia (bph).

PubMed

Roper, W G

2017-03-01

Barry Marshall and Robin Warren were the first to show that the chronic diseases (gastric ulcer and chronic gastritis) were caused by an infection (Helicobacter pylori). The chronic disease benign prostatic hyperplasia belongs to the same ilk, except that the infection process is much more subtle and complex. The enzyme Phospholipase D (PLD) which is attached to the outer membrane of Escherichia coli (E. coli) has now been almost completely proven to be the basic cause of BPH. The evidence for this process is now extremely strong and compelling. PLD obtained from the organism Streptomyces chromofuscus has been used in past research because of its PLD content. It is commercially available. In vitro, on a culture of prostatic smooth muscle, PLD stimulated the production of lysophosphatidic acid (LPA) which acted on and caused substantial growth of that muscle in accordance with the quantity of PLD/ LPA generated. It has been asserted that repeated colonization by E. coli of the transitional zone of the prostate gland and the release of PLD following repeated destruction of these colonized bacteria, is the basic cause of BPH. The evidence for colonizing and re-colonizing infection is now overwhelming. PLD is a simple lipid consisting of a phosphate, glycerol and a fatty acid. After absorption into the prostatic stroma (which consists of connective tissue and of smooth muscle), it stimulates the production of LPA which, in turn, apart from directly stimulating prostatic smooth muscle, also acts on the connective tissue in the prostate and induces a complex mixture of growth regulatory proteins, which include members of the fibroblast, insulin-like and growth transforming factor families and implicates autocrine hormones acting on the stroma and paracrine hormones acting on epithelium. Also involved, are a variety of interleukins and other inflammatory cell cytokines, secreted by the stroma, which may further promote autocrine/paracrine proliferation of BPH cells. Cadherins involved in cell adhesion and possibly chalone which exerts negative effects, must also be considered. Overall, the degree of BPH that any older male develops is governed largely by: Apart from providing the existing huge evidence for infection in BPH, this manuscript explains the production, release and absorption of PLD into the prostate gland where it is converted to LPA. This is a growth factor and acts within the prostate both on smooth muscle (research proof given) and on prostatic connective tissue, resulting in BPH. This manuscript indicates the vital research, including the requisite materials, which would readily provide irrefutable and final etiological proof of all of the hormones involved. It explains how, to a large extent, the use of a vaccine which is now being developed, would likely allow the ultimate prevention of this ubiquitous disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cost Effectiveness Analysis of Different Management Strategies between Best Supportive Care and Second-line Chemotherapy for Platinum-resistant or Refractory Ovarian Cancer.

PubMed

Luealon, Phanida; Khempech, Nipon; Vasuratna, Apichai; Hanvoravongchai, Piya; Havanond, Piyalamporn

2016-01-01

There is no standard treatment for patients with platinum-resistant or refractory epithelial ovarian cancer. Single agent chemotherapies have evidence of more efficacy and less toxicity than combination therapy. Most are very expensive, with appreciable toxicity and minimal survival. Since it is difficult to make comparison between outcomes, economic analysis of single-agent chemotherapy regimens and best supportive care may help to make decisions about an appropriate management for the affected patients. To evaluate the cost effectiveness of second-line chemotherapy compared with best supportive care for patients with platinum-resistant or refractory epithelial ovarian cancer. A Markov model was used to estimate the effectiveness and total costs associated with treatments. The hypothetical patient population comprised women aged 55 with platinum-resistant or refractory epithelial ovarian cancer. Four types of alternative treatment options were evaluated: 1) gemcitabine followed by BSC; 2) pegylated liposomal doxorubicin (PLD) followed by BSC; 3) gemcitabine followed by topotecan; and 4) PLD followed by topotecan. Baseline comparator of alternative treatments was BSC. Time horizon of the analysis was 2 years. Health care provider perspective and 3% discount rate were used to determine the costs of medical treatment in this study. Quality-adjusted life-years (QALY) were used to measure the treatment effectiveness. Treatment effectiveness data were derived from the literature. Costs were calculated from unit cost treatment of epithelial ovarian cancer patients at various stages of disease in King Chulalongkorn Memorial Hospital (KCMH) in the year 2011. Parameter uncertainty was tested in probabilistic sensitivity analysis by using Monte Carlo simulation. One-way sensitivity analysis was used to explore each variable's impact on the uncertainty of the results. Approximated life expectancy of best supportive care was 0.182 years and its total cost was 26,862 Baht. All four alternative treatments increased life expectancy. Life expectancy of gemcitabine followed by BSC, PLD followed by BSC, gemcitabine followed by topotecan and PLD followed by topotecan was 0.510, 0.513, 0.566, and 0.570 years, respectively. The total cost of gemcitabine followed by BSC, PLD followed by BSC, gemcitabine followed by topotecan and PLD followed by topotecan was 113,000, 124,302, 139,788 and 151,135 Baht, respectively. PLD followed by topotecan had the highest expected quality-adjusted life-years but was the most expensive of all the above strategies. The incremental cost-effectiveness ratios (ICER) of gemcitabine followed by BSC, PLD followed by BSC, gemcitabine followed by topotecan and PLD followed by topotecan was 344,643, 385,322, 385,856, and 420,299 Baht, respectively. All of the second-line chemotherapy strategies showed certain benefits due to an increased life- year gained compared with best supportive care. Moreover, gemcitabine as second-line chemotherapy followed by best supportive care in progressive disease case was likely to be more effective strategy with less cost from health care provider perspective. Gemcitabine was the most cost-effective treatment among all four alternative treatments. ICER is only an economic factor. Treatment decisions should be based on the patient benefit.

Using Activity Theory to Evaluate a Professional Learning and Development Initiative in the Use of Narrative Assessment

ERIC Educational Resources Information Center

Bourke, Roseanna; Mentis, Mandia; O'Neill, John

2013-01-01

Analysis of the impact of professional learning and development (PLD) programmes for educators is complex. This article presents an analysis of a PLD initiative in which classroom teachers learned to use narrative assessment for students with "high" and "very high" learning needs. Using Cultural Historical Activity Theory…

Deoxyribonucleoprotein structure and radiation injury - Cellular radiosensitivity is determined by LET-infinity-dependent DNA damage in hydrated deoxyribonucleoproteins and the extent of its repair

NASA Technical Reports Server (NTRS)

Lett, J. T.; Peters, E. L.

1992-01-01

Until recently, OH radicals formed in bulk nuclear water were believed to be the major causes of DNA damage that results in cell death, especially for sparsely ionizing radiations. That hypothesis has now been challenged, if not refuted. Lethal genomic DNA damage is determined mainly by energy deposition in deoxyribonucleoproteins, and their hydration shells, and charge (energy) transfer processes within those structures.

Morphological differentiation of N1E-115 neuroblastoma cells by dimethyl sulfoxide activation of lipid second messengers.

PubMed

Clejan, S; Dotson, R S; Wolf, E W; Corb, M P; Ide, C F

1996-04-10

Quantitative changes in the lipid second messenger diacylglycerol (DAG) were studied in the rat neuroblastoma N1E-115 following exposure to the differentiating agent dimethylsulfoxide (DMSO). Relatively high basal levels of DAG are present in these cells, and addition of 2% DMSO elicited a biphasic increase in DAG levels, dependent on the presence of extracellular Ca2+. Exposure to DMSO also elicited a rapid increase in inositol phosphate and a slight increase in phosphatidic acid (PA), trailing that of DAG. The molecular species (MS) of DAG were analyzed. Within 60 s of DMSO application there were transient increases of DAG representative of phosphatidylinositol (PI) hydrolysis. At longer intervals, more DAG originated from phosphatidylcholine. The MS composition of newly formed PA resembled that of PI and native DAG. Inhibition studies indicated that DAG is formed in the DMSO-treated cells by phospholipases C and that PA formed later is a result of DAG phosphorylation and not activity of phospholipase D (PLD). Undifferentiated cells exhibited an active PLD pathway. In contrast, PLD in DMSO-differentiated cells was not active. In examining the involvement of the sphingomyelin pathway, DMSO exposure was found to increase ceramide levels with a concomitant decrease in sphingomyelin. Addition of the exogenous, soluble analog C6-ceramide to undifferentiated cells resulted in dramatic reductions in DAG and PA levels and PLD activity. These results indicate that DMSO treatment inactivates PLD while activating phospholipases C and the sphingomyelin pathway, suggesting a "switch" between signal transduction pathways in the undifferentiated and differentiated states of N1E-115.

Insulin stimulates phospholipase D-dependent phosphatidylcholine hydrolysis, Rho translocation, de novo phospholipid synthesis, and diacylglycerol/protein kinase C signaling in L6 myotubes.

PubMed

Standaert, M L; Bandyopadhyay, G; Zhou, X; Galloway, L; Farese, R V

1996-07-01

Previous studies have provided conflicting findings on whether insulin activates certain, potentially important, phospholipid signaling systems in skeletal muscle preparations. In particular, insulin effects on the hydrolysis of phosphatidylcholine (PC) and subsequent activation of protein kinase C (PKC) have not been apparent in some studies. Presently, we examined insulin effects on phospholipid signaling systems, diacylglycerol (DAG) production, and PKC translocation/activation in L6 myotubes. We found that insulin provoked rapid increases in phospholipase D (PLD)-dependent hydrolysis of PC, as evidenced by increases in choline release and phosphatidylethanol production in cells incubated in the presence of ethanol. In association with PC-PLD activation, Rho, a small G protein that is known to activate PC-PLD activation, translocated from the cytosol to the membrane fraction in response to insulin treatment. PC-PLD activation was also accompanied by increases in total DAG production and increases in the translocation of both PKC enzyme activity and DAG-sensitive PKC-alpha, -beta, -delta, and -epsilon from the cytosol to the membrane fraction. A potential role for PKC or a related protein kinase in insulin action was suggested by the finding that RO 31-8220 inhibited both PKC enzyme activity and insulin-stimulated [3H]2-deoxyglucose uptake. Our findings provide the first evidence that insulin stimulates Rho translocation and activates PC-PLD in L6 skeletal muscle cells. Moreover, this signaling system appears to lead to increases in DAG/PKC signaling, which, along with other related signaling factors, may regulate certain metabolic processes, such as glucose transport, in these cells.

Phosphatidic acid (PA) binds PP2AA1 to regulate PP2A activity and PIN1 polar localization.

PubMed

Gao, Hong-Bo; Chu, Yu-Jia; Xue, Hong-Wei

2013-09-01

Phospholipase D (PLD) exerts broad biological functions in eukaryotes through regulating downstream effectors by its product, phosphatidic acid (PA). Protein kinases and phosphatases, such as mammalian target of rapamycin (mTOR), Protein Phosphatase 1 (PP1) and Protein Phosphatase 2C (PP2C), are PA-binding proteins that execute crucial regulatory functions in both animals and plants. PA participates in many signaling pathways by modulating the enzymatic activity and/or subcellular localization of bound proteins. In this study, we demonstrated that PLD-derived PA interacts with the scaffolding A1 subunit of Protein Phosphatase 2A (PP2A) and regulates PP2A-mediated PIN1 dephosphorylation in Arabidopsis. Genetic and pharmacological studies showed that both PA and PP2A participate in the regulation of auxin distribution. In addition, both the phosphorylation status and polar localization of PIN1 protein were affected by PLD inhibitors. Exogenous PA triggered the membrane accumulation of PP2AA1 and enhanced the PP2A activity at membrane, while PLD inhibition resulted in the reduced endosomal localization and perinuclear aggregation of PP2AA1. These results demonstrate the important role of PLD-derived PA in normal PP2A-mediated PIN dephosphorylation and reveal a novel mechanism, in which PA recruits PP2AA1 to the membrane system and regulates PP2A function on membrane-targeted proteins. As PA and PP2A are conserved among eukaryotes, other organisms might use similar mechanisms to mediate multiple biological processes.

Hyper-activated motility in sperm capacitation is mediated by phospholipase D-dependent actin polymerization.

PubMed

Itach, Sarit Bar-Sheshet; Finklestein, Maya; Etkovitz, Nir; Breitbart, Haim

2012-02-15

In order to fertilize the oocyte, sperm must undergo a series of biochemical changes in the female reproductive tract, known as capacitation. Once capacitated, spermatozoon can bind to the zona pellucida of the egg and undergo the acrosome reaction (AR), a process that enables its penetration and fertilization of the oocyte. Important processes that characterize sperm capacitation are actin polymerization and the development of hyper-activated motility (HAM). Previously, we showed that Phospholipase D (PLD)-dependent actin polymerization occurs during sperm capacitation, however the role of this process in sperm capacitation is not yet known. In the present study, we showed for the first time the involvement of PLD-dependent actin polymerization in sperm motility during mouse and human capacitation. Sperm incubated under capacitation conditions revealed a time dependent increase in actin polymerization and HAM. Inhibition of Phosphatidic Acid (PA) formation by PLD using butan-1-ol, inhibited actin polymerization and motility, as well as in vitro fertilization (IVF) and the ability of the sperm to undergo the AR. The inhibition of sperm HAM by low concentration of butan-1-ol is completely restored by adding PA, further indicating the involvement of PLD in these processes. Furthermore, exogenous PA enhanced rapid actin polymerization that was followed by a rise in the HAM, as well as an increased in IVF rate. In conclusion, our results demonstrate that PLD-dependent actin polymerization is a critical step needed for the development of HAM during mouse and human sperm capacitation. Copyright © 2011 Elsevier Inc. All rights reserved.

Infant brain activity while viewing facial movement of point-light displays as measured by near-infrared spectroscopy (NIRS).

PubMed

Ichikawa, Hiroko; Kanazawa, So; Yamaguchi, Masami K; Kakigi, Ryusuke

2010-09-27

Adult observers can quickly identify specific actions performed by an invisible actor from the points of lights attached to the actor's head and major joints. Infants are also sensitive to biological motion and prefer to see it depicted by a dynamic point-light display. In detecting biological motion such as whole body and facial movements, neuroimaging studies have demonstrated the involvement of the occipitotemporal cortex, including the superior temporal sulcus (STS). In the present study, we used the point-light display technique and near-infrared spectroscopy (NIRS) to examine infant brain activity while viewing facial biological motion depicted in a point-light display. Dynamic facial point-light displays (PLD) were made from video recordings of three actors making a facial expression of surprise in a dark room. As in Bassili's study, about 80 luminous markers were scattered over the surface of the actor's faces. In the experiment, we measured infant's hemodynamic responses to these displays using NIRS. We hypothesized that infants would show different neural activity for upright and inverted PLD. The responses were compared to the baseline activation during the presentation of individual still images, which were frames extracted from the dynamic PLD. We found that the concentration of oxy-Hb increased in the right temporal area during the presentation of the upright PLD compared to that of the baseline period. This is the first study to demonstrate that infant's brain activity in face processing is induced only by the motion cue of facial movement depicted by dynamic PLD. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Cultural and Demographic Factors Influencing Noise Exposure Estimates from Use of Portable Listening Devices in an Urban Environment

ERIC Educational Resources Information Center

Fligor, Brian J.; Levey, Sandra; Levey, Tania

2014-01-01

Purpose: This study examined listening levels and duration of portable listening devices (PLDs) used by people with diversity of ethnicity, education, music genre, and PLD manufacturer. The goal was to estimate participants' PLD noise exposure and identify factors influencing user behavior. Method: This study measured listening levels of 160…

The Functional Communication Skills of Boys with Externalising Behaviour with and without Co-Occurring Language Difficulties

ERIC Educational Resources Information Center

Mackie, Leila; Law, James

2014-01-01

Previous studies have highlighted a high level of language impairment (LI) and pragmatic language disorder (PLD) amongst children with social, emotional and behavioural difficulties (SEBD). However, little is known regarding the impact of LI in the severity of PLD in this group. This study investigates the language and pragmatic language skills of…

An improved continuous compositional-spread technique based on pulsed-laser deposition and applicable to large substrate areas

NASA Astrophysics Data System (ADS)

Christen, H. M.; Rouleau, C. M.; Ohkubo, I.; Zhai, H. Y.; Lee, H. N.; Sathyamurthy, S.; Lowndes, D. H.

2003-09-01

A method for continuous compositional-spread (CCS) thin-film fabrication based on pulsed-laser deposition (PLD) is introduced. This approach is based on a translation of the substrate heater and the synchronized firing of the excimer laser, with the deposition occurring through a slit-shaped aperture. Alloying is achieved during film growth (possible at elevated temperature) by the repeated sequential deposition of submonolayer amounts. Our approach overcomes serious shortcomings in previous in situ implementation of CCS based on sputtering or PLD, in particular the variation of thickness across the compositional spread and the differing deposition energetics as a function of position. While moving-shutter techniques are appropriate for PLD approaches yielding complete spreads on small substrates (i.e., small as compared to distances over which the deposition parameters in PLD vary, typically ≈1 cm), our method can be used to fabricate samples that are large enough for individual compositions to be analyzed by conventional techniques, including temperature-dependent measurements of resistivity and dielectric and magnetic properties (i.e., superconducting quantum interference device magnetometry). Initial results are shown for spreads of (Sr1-xCax)RuO3.

A Single Nucleotide Polymorphism in the Phospholipase D1 Gene is Associated with Risk of Non-Small Cell Lung Cancer

PubMed Central

Ahn, Myung-Ju; Park, Shin-Young; Kim, Won Kyu; Cho, Ju Hwan; Chang, Brian Junho; Kim, Dong Jo; Ahn, Jin Seok; Park, Keunchil; Han, Joong-Soo

2012-01-01

Phospholipase D (PLD) has an important role in various biological functions including vesicular transport, endocytosis, exocytosis, cell migration, and mitosis. These cellular biological processes are deregulated in the development of various human tumors. In order to explore the relationship between the PLD1 gene and risk of non-small cell lung cancer (NSCLC), single nucleotide polymorphisms (SNP) in the PLD1 exon region were surveyed in 211 NSCLC patients and 205 normal controls. In this study, we identified six SNPs at exon 23 in the PLD1 gene. Among the six SNPs, the most notable was a heterozygous A to C transition at nucleotide 2698 (A2698C, p<0.001). In addition, the genotype frequencies of A2744C (AC+CC) and A2756C (AC+CC) were associated with gender (female, A2744C and A2756C: p=0.071) in NSCLC patients. Interestingly, although the SNP A2698C did not cause change in amino acid, correlation between odd ratio of NSCLC patients and the SNP A2698C was observed to be statistically significant. PMID:23675264

Measuring phospholipase D activity in insulin-secreting pancreatic beta-cells and insulin-responsive muscle cells and adipocytes.

PubMed

Cazzolli, Rosanna; Huang, Ping; Teng, Shuzhi; Hughes, William E

2009-01-01

Phospholipase D (PLD) is an enzyme producing phosphatidic acid and choline through hydrolysis of phosphatidylcholine. The enzyme has been identified as a member of a variety of signal transduction cascades and as a key regulator of numerous intracellular vesicle trafficking processes. A role for PLD in regulating glucose homeostasis is emerging as the enzyme has recently been identified in events regulating exocytosis of insulin from pancreatic beta-cells and also in insulin-stimulated glucose uptake through controlling GLUT4 vesicle exocytosis in muscle and adipose tissue. We present methodologies for assessing cellular PLD activity in secretagogue-stimulated insulin-secreting pancreatic beta-cells and also insulin-stimulated adipocyte and muscle cells, two of the principal insulin-responsive cell types controlling blood glucose levels.

Pulsed laser deposition of plasmonic nanostructured gold on flexible transparent polymers at atmospheric pressure

NASA Astrophysics Data System (ADS)

McCann, Ronán; Hughes, Cian; Bagga, Komal; Stalcup, Apryll; Vázquez, Mercedes; Brabazon, Dermot

2017-06-01

In this paper, we outline a novel technique for the deposition of nanostructured thin films utilizing a modified form of pulsed laser deposition (PLD). We demonstrate confined atmospheric PLD (CAP) for the deposition of gold on cyclic olefin polymer substrates. The deposition process is a simplified form of conventional PLD, with deposition conducted under atmospheric conditions and the substrate and target in close proximity. It was found that this confinement results in the deposition of nanostructured thin films on the substrate. Infrared spectroscopy showed no significant change of polymer surface chemistry as a result of the deposition process, and optical spectroscopy revealed plasmonic behavior of the resulting thin film. The effect of laser fluence on the deposition process was also examined with more uniform films deposited at higher fluences.

Reducing the risk of music-induced hearing loss from overuse of portable listening devices: understanding the problems and establishing strategies for improving awareness in adolescents.

PubMed

Portnuff, Cory Df

2016-01-01

Hearing loss from the overuse of portable listening devices (PLDs), such as MP3 players or iPods, is of great concern in the popular media. This review aims to discuss the current state of scientific knowledge about music-induced hearing loss from PLD use. This report evaluates the literature on the risk to hearing from PLD use, the individual and psychological factors that influence PLD usage, and strategies for reducing exposure to music through PLDs. Specific interventions are reviewed, and several recommendations for designing interventions and for individual intervention in clinical practice are presented. Clinical recommendations suggested include the "80-90 rule" and the use of isolator-style earphones to reduce background noise.

Reducing the risk of music-induced hearing loss from overuse of portable listening devices: understanding the problems and establishing strategies for improving awareness in adolescents

PubMed Central

Portnuff, Cory DF

2016-01-01

Hearing loss from the overuse of portable listening devices (PLDs), such as MP3 players or iPods, is of great concern in the popular media. This review aims to discuss the current state of scientific knowledge about music-induced hearing loss from PLD use. This report evaluates the literature on the risk to hearing from PLD use, the individual and psychological factors that influence PLD usage, and strategies for reducing exposure to music through PLDs. Specific interventions are reviewed, and several recommendations for designing interventions and for individual intervention in clinical practice are presented. Clinical recommendations suggested include the “80–90 rule” and the use of isolator-style earphones to reduce background noise. PMID:26929674

Ricin crosses polarized human intestinal cells and intestines of ricin-gavaged mice without evident damage and then disseminates to mouse kidneys.

PubMed

Flora, Alyssa D; Teel, Louise D; Smith, Mark A; Sinclair, James F; Melton-Celsa, Angela R; O'Brien, Alison D

2013-01-01

Ricin is a potent toxin found in the beans of Ricinus communis and is often lethal for animals and humans when aerosolized or injected and causes significant morbidity and occasional death when ingested. Ricin has been proposed as a bioweapon because of its lethal properties, environmental stability, and accessibility. In oral intoxication, the process by which the toxin transits across intestinal mucosa is not completely understood. To address this question, we assessed the impact of ricin on the gastrointestinal tract and organs of mice after dissemination of toxin from the gut. We first showed that ricin adhered in a specific pattern to human small bowel intestinal sections, the site within the mouse gut in which a variable degree of damage has been reported by others. We then monitored the movement of ricin across polarized human HCT-8 intestinal monolayers grown in transwell inserts and in HCT-8 cell organoids. We observed that, in both systems, ricin trafficked through the cells without apparent damage until 24 hours post intoxication. We delivered a lethal dose of purified fluorescently-labeled ricin to mice by oral gavage and followed transit of the toxin from the gastrointestinal tracts to the internal organs by in vivo imaging of whole animals over time and ex vivo imaging of organs at various time points. In addition, we harvested organs from unlabeled ricin-gavaged mice and assessed them for the presence of ricin and for histological damage. Finally, we compared serum chemistry values from buffer-treated versus ricin-intoxicated animals. We conclude that ricin transverses human intestinal cells and mouse intestinal cells in situ prior to any indication of enterocyte damage and that ricin rapidly reaches the kidneys of intoxicated mice. We also propose that mice intoxicated orally with ricin likely die from distributive shock.

Ricin Crosses Polarized Human Intestinal Cells and Intestines of Ricin-Gavaged Mice without Evident Damage and Then Disseminates to Mouse Kidneys

PubMed Central

Flora, Alyssa D.; Teel, Louise D.; Smith, Mark A.; Sinclair, James F.; Melton-Celsa, Angela R.; O’Brien, Alison D.

2013-01-01

Ricin is a potent toxin found in the beans of Ricinus communis and is often lethal for animals and humans when aerosolized or injected and causes significant morbidity and occasional death when ingested. Ricin has been proposed as a bioweapon because of its lethal properties, environmental stability, and accessibility. In oral intoxication, the process by which the toxin transits across intestinal mucosa is not completely understood. To address this question, we assessed the impact of ricin on the gastrointestinal tract and organs of mice after dissemination of toxin from the gut. We first showed that ricin adhered in a specific pattern to human small bowel intestinal sections, the site within the mouse gut in which a variable degree of damage has been reported by others. We then monitored the movement of ricin across polarized human HCT-8 intestinal monolayers grown in transwell inserts and in HCT-8 cell organoids. We observed that, in both systems, ricin trafficked through the cells without apparent damage until 24 hours post intoxication. We delivered a lethal dose of purified fluorescently-labeled ricin to mice by oral gavage and followed transit of the toxin from the gastrointestinal tracts to the internal organs by in vivo imaging of whole animals over time and ex vivo imaging of organs at various time points. In addition, we harvested organs from unlabeled ricin-gavaged mice and assessed them for the presence of ricin and for histological damage. Finally, we compared serum chemistry values from buffer-treated versus ricin-intoxicated animals. We conclude that ricin transverses human intestinal cells and mouse intestinal cells in situ prior to any indication of enterocyte damage and that ricin rapidly reaches the kidneys of intoxicated mice. We also propose that mice intoxicated orally with ricin likely die from distributive shock. PMID:23874986

Neoplastic cell transformation by high-LET radiation - Molecular mechanisms

NASA Technical Reports Server (NTRS)

Yang, Tracy Chui-Hsu; Craise, Laurie M.; Tobias, Cornelius A.; Mei, Man-Tong

1989-01-01

Quantitative data were collected on dose-response curves of cultured mouse-embryo cells (C3H10T1/2) irradiated with heavy ions of various charges and energies. Results suggests that two breaks formed on DNA within 80 A may cause cell transformation and that two DNA breaks formed within 20 A may be lethal. From results of experiments with restriction enzymes which produce DNA damages at specific sites, it was found that DNA double strand breaks are important primary lesions for radiogenic cell transformation and that blunt-ended double-strand breaks can form lethal as well as transformational damages due to misrepair or incomplete repair in the cell. The RBE-LET relationship for high-LET radiation is similar to that for HGPRT locus mutation, chromosomal deletion, and cell transformation, indicating that common lesions may be involved in these radiation effects.

ATR Kinase Inhibition Protects Non-cycling Cells from the Lethal Effects of DNA Damage and Transcription Stress*

PubMed Central

Kemp, Michael G.; Sancar, Aziz

2016-01-01

ATR (ataxia telangiectasia and Rad-3-related) is a protein kinase that maintains genome stability and halts cell cycle phase transitions in response to DNA lesions that block DNA polymerase movement. These DNA replication-associated features of ATR function have led to the emergence of ATR kinase inhibitors as potential adjuvants for DNA-damaging cancer chemotherapeutics. However, whether ATR affects the genotoxic stress response in non-replicating, non-cycling cells is currently unknown. We therefore used chemical inhibition of ATR kinase activity to examine the role of ATR in quiescent human cells. Although ATR inhibition had no obvious effects on the viability of non-cycling cells, inhibition of ATR partially protected non-replicating cells from the lethal effects of UV and UV mimetics. Analyses of various DNA damage response signaling pathways demonstrated that ATR inhibition reduced the activation of apoptotic signaling by these agents in non-cycling cells. The pro-apoptosis/cell death function of ATR is likely due to transcription stress because the lethal effects of compounds that block RNA polymerase movement were reduced in the presence of an ATR inhibitor. These results therefore suggest that whereas DNA polymerase stalling at DNA lesions activates ATR to protect cell viability and prevent apoptosis, the stalling of RNA polymerases instead activates ATR to induce an apoptotic form of cell death in non-cycling cells. These results have important implications regarding the use of ATR inhibitors in cancer chemotherapy regimens. PMID:26940878

Injury Risk Assessment of Non-Lethal Projectile Head Impacts

PubMed Central

Oukara, Amar; Nsiampa, Nestor; Robbe, Cyril; Papy, Alexandre

2014-01-01

Kinetic energy non-lethal projectiles are used to impart sufficient effect onto a person in order to deter uncivil or hazardous behavior with a low probability of permanent injury. Since their first use, real cases indicate that the injuries inflicted by such projectiles may be irreversible and sometimes lead to death, especially for the head impacts. Given the high velocities and the low masses involved in such impacts, the assessment approaches proposed in automotive crash tests and sports may not be appropriate. Therefore, there is a need of a specific approach to assess the lethality of these projectiles. In this framework, some recent research data referred in this article as “force wall approach” suggest the use of three lesional thresholds (unconsciousness, meningeal damages and bone damages) that depend on the intracranial pressure. Three corresponding critical impact forces are determined for a reference projectile. Based on the principle that equal rigid wall maximal impact forces will produce equal damage on the head, these limits can be determined for any other projectile. In order to validate the consistence of this innovative method, it is necessary to compare the results with other existing assessment methods. This paper proposes a comparison between the “force wall approach” and two different head models. The first one is a numerical model (Strasbourg University Finite Element Head Model-SUFEHM) from Strasbourg University; the second one is a mechanical surrogate (Ballistics Load Sensing Headform-BLSH) from Biokinetics. PMID:25400712

Ethylhexylglycerin Impairs Membrane Integrity and Enhances the Lethal Effect of Phenoxyethanol

PubMed Central

Langsrud, Solveig; Steinhauer, Katrin; Lüthje, Sonja; Weber, Klaus; Goroncy-Bermes, Peter; Holck, Askild L.

2016-01-01

Preservatives are added to cosmetics to protect the consumers from infections and prevent product spoilage. The concentration of preservatives should be kept as low as possible and this can be achieved by adding potentiating agents. The aim of the study was to investigate the mechanisms behind potentiation of the bactericidal effect of a commonly used preservative, 2-phenoxyethanol (PE), by the potentiating agent ethylhexylglycerin (EHG). Sub-lethal concentrations of EHG (0.075%) and PE (0.675%) in combination led to rapid killing of E. coli (> 5 log reduction of cfu after 30 min), leakage of cellular constituents, disruption of the energy metabolism, morphological deformities of cells and condensation of DNA. Used alone, EHG disrupted the membrane integrity even at low concentrations. In conclusion, sub-lethal concentrations of EHG potentiate the effect of PE through damage of the cell membrane integrity. Thus, adding EHG to PE in a 1:9 ratio has a similar effect on membrane damage and bacterial viability as doubling the concentration of PE. This study provides insight about the mechanism of action of a strong potentiating agent, EHG, which is commonly used in cosmetics together with PE. PMID:27783695

Evaluation of the performance of three elastomers for non-lethal projectile applications

NASA Astrophysics Data System (ADS)

Thota, N.; Epaarachchi, J.; Lau, K. T.

2015-09-01

Less lethal kinetic ammunitions with soft noses such as eXact iMpact 1006, National Sports Spartan and B&T have been commonly used by military and law enforcement officers in the situations where lethal force is not warranted. In order to explore new materials to be used as nose in such ammunitions, a scholastic study using finite element simulations has been carried out to evaluate the effectiveness of two rubber like elastomers and a polyolefinic foam (low density, highly compressible, stiff and closed cell type of thermos plastic elastomer). State-of-the art thorax surrogate MTHOTA has been employed for the evaluation of blunt thoracic trauma. Force-rigid wall method was employed for the evaluation of head damage curves for each material. XM 1006 has been used as the benchmark projectile for the purpose of comparison. Both blunt thoracic trauma and head damage criterion point of view, both rubbers (R1 and R2) have yielded high values of VCmax and peak impact force. Polyolefinic foam (F1) considered in the study has yielded very promising VCmax values and very less peak impact force when compared with those of bench mark projectile XM 1006.

Group Work: Pleasure or Pain? An Effective Guidance Activity or a Poor Substitute for One-to-One Interactions with Young People?

ERIC Educational Resources Information Center

Westergaard, Jane

2013-01-01

This paper defines the concept of personal learning and development (PLD) group work as a guidance activity in both career counselling and youth support practice. It introduces the FAAST model-a framework for planning, preparing and delivering PLD group sessions (Westergaard in Effective group work with young people. Open University, Maidenhead,…

Serine protease-related proteins in the malaria mosquito, Anopheles gambiae.

PubMed

Cao, Xiaolong; Gulati, Mansi; Jiang, Haobo

2017-09-01

Insect serine proteases (SPs) and serine protease homologs (SPHs) participate in digestion, defense, development, and other physiological processes. In mosquitoes, some clip-domain SPs and SPHs (i.e. CLIPs) have been investigated for possible roles in antiparasitic responses. In a recent test aimed at improving quality of gene models in the Anopheles gambiae genome using RNA-seq data, we observed various discrepancies between gene models in AgamP4.5 and corresponding sequences selected from those modeled by Cufflinks, Trinity and Bridger. Here we report a comparative analysis of the 337 SP-related proteins in A. gambiae by examining their domain structures, sequence diversity, chromosomal locations, and expression patterns. One hundred and ten CLIPs contain 1 to 5 clip domains in addition to their protease domains (PDs) or non-catalytic, protease-like domains (PLDs). They are divided into five subgroups: CLIPAs (22) are clip 1-5 -PLD; CLIPBs (29), CLIPCs (12) and CLIPDs (14) are mainly clip-PD; most CLIPEs (33) have a domain structure of PD/PLD-PLD-clip-PLD 0-1 . While expression of the CLIP genes in group-1 is generally low and detected in various tissue- and stage-specific RNA-seq libraries, some putative GPs/GPHs (i.e. single domain gut SPs/SPHs) in group-2 are highly expressed in midgut, whole larva or whole adult libraries. In comparison, 46 SPs, 26 SPHs, and 37 multi-domain SPs/SPHs (i.e. PD/PLD-PLD ≥1 ) in group-3 do not seem to be specifically expressed in digestive tract. There are 16 SPs and 2 SPH containing other types of putative regulatory domains (e.g. LDLa, CUB, Gd). Of the 337 SP and SPH genes, 159 were sorted into 46 groups (2-8 members/group) based on similar phylogenetic tree position, chromosomal location, and expression profile. This information and analysis, including improved gene models and protein sequences, constitute a solid foundation for functional analysis of the SP-related proteins in A. gambiae. Copyright © 2017 Elsevier Ltd. All rights reserved.

The role of proximal body information on anticipatory judgment in tennis using graphical information richness.

PubMed

Fukuhara, Kazunobu; Ida, Hirofumi; Ogata, Takahiro; Ishii, Motonobu; Higuchi, Takahiro

2017-01-01

Recent studies have reported that skilled tennis players are likely to use proximal body information for anticipating the direction of their opponent's forehand shot. However, in these studies, the visual stimuli did not include visual information about the ball. Skilled players may have used proximal information owing to the lack of distal information. To address this issue, we developed a novel methodological approach using computer graphics (CG) images in which the entire body was presented by a combination of point-light display (i.e., poor graphical information, PLD) and polygons (i.e., rich graphical information). Using our novel methodological approach, we examined whether skilled tennis players use proximal body information when anticipating shot directions. Fifteen skilled tennis players and fifteen novice players tried to anticipate shot directions by observing four CG forehand strokes (ALPOL: all body parts were represented with polygon; RAPLD: racket and arm were represented with PLD; BOPLD: body parts without racket and arm were represented with PLD; and ALPLD: all body parts were represented with PLD). Our intention in creating CG models with such combinations (i.e., RAPLD and BOPLD) was that because of the richer graphical information provided by polygons compared to PLD, the participant's anticipatory judgment would be influenced more by body parts expressed with polygons. The results showed that for skilled players, anticipatory judgment was more accurate when they observed RAPLD than when they observed BOPLD and ALPLD. In contrast, for novice players, there were no differences in the accuracy of anticipatory judgments with the four CG models. Only skilled players made more accurate anticipatory judgments when body regions were expressed with rich graphical information, and the racket and arm were expressed with poor graphical information. These suggest that skilled players used proximal information to effectively anticipate shot directions.

Altered activity of lysophospholipase D, which produces bioactive lysophosphatidic acid and choline, in serum from women with pathological pregnancy.

PubMed

Tokumura, A; Kume, T; Taira, S; Yasuda, K; Kanzaki, H

2009-05-01

Altered lipid metabolism is associated with human abnormal pregnancy, such as pre-eclampsia and preterm labor, and potentially leads to fetus loss. A causative factor for the onset and progress of the systemic multifactorial syndromes associated with the pathological pregnancy is oxidized low-density lipoprotein, an active identity of which was postulated to be lysophosphatidic acid (LPA). We previously found that LPA is produced extracellularly by plasma lysophospholipase D (lysoPLD) activity of autotaxin, a tumor cell motility-stimulating protein. In this study, a convenient assay based on the choline released from endogenous substrate or exogenous lysophosphatidylcholine (LPC) was used for comparison of serum lysoPLD activity among patients with normal and abnormal pregnancy. The serum choline-producing activity was found to be mainly due to autotaxin, and dependent on its dilution rate. There was some association between low dilution dependency of serum lysoPLD activity toward an exogenous LPC and high lysoPLD activity toward endogenous substrates in cases of patients with preterm labor and pre-eclampsia. However, there was no difference in the serum level of LPC between women with normal pregnancy and those with pathological pregnancy. These results indicate that production of bioactive LPA by lysoPLD activity is elevated by an unknown mechanism that may be related to increased availability of endogenous substrates LPC, but not its concentration in human serum. If the level of LPA in blood circulation is elevated in the pathological pregnancies in vivo, it may play a role in induction and/or progression of systemic vascular dysfunction seen patients with preterm labor or pre-eclampsia.

RAPESEED PHOSPHATIDYLCHOLINE HYDROLYSIS TO PHOSPHATIDIC ACID USING PLANT EXTRACTS WITH PHOPSPHOLIPASE D.

PubMed

Pasker, Beata; Sosada, Marian; Fraś, Paweł; Boryczka, Monika; Górecki, Michał; Zych, Maria

2015-01-01

Phosphatidic acid (PA) has a crucial role in cell membrane structure and function. For that reason it has a possible application in the treatment of some health disorders in humans, can be used as a natural and non toxic emulsifier and the component of drug carriers in pharmaceuticals and cosmetics as well as a component for synthesis of some new phospholipids. PA is short-lived in the cell and is difficult to extract directly from the biological material. PA may be easily prepared by hydrolysis of phospholipids, especially phosphatidylcholine (PC), using cabbage phospholipase D (PLD). Hydrolytic activity of purified by us PLD extracts from cabbage towards rapeseed phosphatidylcholine (RPC) was investigated. Hydrolysis was carried out in the biphasic system (water/diethyl ether) at pH 6,5 and temp 30°C. Influence of enzymatic extracts from three cabbage varieties, reaction time, Ca2+ concentration and enzyme extracts/PC ratio, on activity towards RPC resulting in rapeseed phosphatidic acid (RPA) formation were examined. Our study shows that the PLD extracts from savoy cabbage (PLDsc), white cabbage (PLDwc) and brussels sprouts (PLDbs) used in experiments exhibit hydrolytic activity towards RPC resulting in rapeseed RPA with different yield. The highest activity towards RPC shows PLD extract from PLDsc with the RPC conversion degree to RPA (90%) was observed at 120 mM Ca2+ concentration, reaction time 60 min and ratio of PLD extract to RPC 6 : 1 (w/w). Our study shows that purified by us PLDsc extracts exhibit hydrolytic activity towards RPC giving new RPA with satisfying conversion degree for use in pharmacy, cosmetics and as a standard in analytical chemistry.

In-situ monitoring by reflective high energy electron diffraction during pulsed laser deposition

NASA Astrophysics Data System (ADS)

Blank, Dave H. A.; Rijnders, Guus J. H. M.; Koster, Gertjan; Rogalla, Horst

1999-01-01

Pulsed laser deposition (PLD) has developed during the past decade from a fast but limited preparation tool towards a competitive thin film deposition technique. One of the advantages above other techniques is the possibility of growth at relative high background pressure. There is a large freedom in choosing which kind of gas. Moreover, in a number of applications, the gaseous species in the background pressure are part of the elements to be grown, e.g., oxygen in the case of high Tc superconductors. However, the advantage of relative high pressures leads to restrictions of using standard diagnostics and monitoring of the film growth, e.g., reflective high energy electron diffraction (RHEED). Here, a PLD chamber including an in-situ RHEED system is presented, which makes it possible to monitor and study the growth at standard PLD parameters. Using a two-stages differential pumped, magnetically shielded, extension tube mounted at the electron gun side and a special designed phosphor screen including CCD camera, real time monitoring by observation of RHEED oscillations could be established at pressures up to 50 Pa. In this paper the latest results on applying this technique on SrTiO 3 and YBa 2Cu 3O 7 will be presented. Additional to the usual diagnostics performed with RHEED, another phenomena can be observed. The pulsed way of deposition, characteristic for PLD, leads to relaxations in the intensity of the diffracted pattern due to the mobility of the deposited material. These relaxation times give extra information about relaxation, crystallization, and nucleation of the deposited material. The presented technique leads to a better understanding of the growth during pulsed laser deposition and, because of the possibility to monitor the growth, will make PLD competitive with other deposition techniques.

The Dynamic Changes of the Plasma Membrane Proteins and the Protective Roles of Nitric Oxide in Rice Subjected to Heavy Metal Cadmium Stress

PubMed Central

Yang, Liming; Ji, Jianhui; Harris-Shultz, Karen R.; Wang, Hui; Wang, Hongliang; Abd-Allah, Elsayed F.; Luo, Yuming; Hu, Xiangyang

2016-01-01

The heavy metal cadmium is a common environmental contaminant in soils and has adverse effects on crop growth and development. The signaling processes in plants that initiate cellular responses to environmental stress have been shown to be located in the plasma membrane (PM). A better understanding of the PM proteome in response to environmental stress might provide new insights for improving stress-tolerant crops. Nitric oxide (NO) is reported to be involved in the plant response to cadmium (Cd) stress. To further investigate how NO modulates protein changes in the plasma membrane during Cd stress, a quantitative proteomics approach based on isobaric tags for relative and absolute quantification (iTRAQ) was used to identify differentially regulated proteins from the rice plasma membrane after Cd or Cd and NO treatment. Sixty-six differentially expressed proteins were identified, of which, many function as transporters, ATPases, kinases, metabolic enzymes, phosphatases, and phospholipases. Among these, the abundance of phospholipase D (PLD) was altered substantially after the treatment of Cd or Cd and NO. Transient expression of the PLD fused with green fluorescent peptide (GFP) in rice protoplasts showed that the Cd and NO treatment promoted the accumulation of PLD in the plasma membrane. Addition of NO also enhanced Cd-induced PLD activity and the accumulation of phosphatidic acid (PA) produced through PLD activity. Meanwhile, NO elevated the activities of antioxidant enzymes and caused the accumulation of glutathione, both which function to reduce Cd-induced H2O2 accumulation. Taken together, we suggest that NO signaling is associated with the accumulation of antioxidant enzymes, glutathione and PA which increases cadmium tolerance in rice via the antioxidant defense system. PMID:26955374

Modified Stranski-Krastanov growth in Ge/Si heterostructures via nanostenciled pulsed laser deposition.

PubMed

MacLeod, J M; Cojocaru, C V; Ratto, F; Harnagea, C; Bernardi, A; Alonso, M I; Rosei, F

2012-02-17

The combination of nanostenciling with pulsed laser deposition (PLD) provides a flexible, fast approach for patterning the growth of Ge on Si. Within each stencilled site, the morphological evolution of the Ge structures with deposition follows a modified Stranski-Krastanov (SK) growth mode. By systematically varying the PLD parameters (laser repetition rate and number of pulses) on two different substrate orientations (111 and 100), we have observed corresponding changes in growth morphology, strain and elemental composition using scanning electron microscopy, atomic force microscopy and μ-Raman spectroscopy. The growth behaviour is well predicted within a classical SK scheme, although the Si(100) growth exhibits significant relaxation and ripening with increasing coverage. Other novel aspects of the growth include the increased thickness of the wetting layer and the kinetic control of Si/Ge intermixing via the PLD repetition rate.

Fabrication of 100 A class, 1 m long coated conductor tapes by metal organic chemical vapor deposition and pulsed laser deposition

NASA Astrophysics Data System (ADS)

Selvamanickam, V.; Lee, H. G.; Li, Y.; Xiong, X.; Qiao, Y.; Reeves, J.; Xie, Y.; Knoll, A.; Lenseth, K.

2003-10-01

SuperPower has been scaling up YBa 2Cu 3O x-based second-generation superconducting tapes by techniques such as pulsed laser deposition (PLD) using industrial laser and metal organic chemical vapor deposition (MOCVD). Both techniques offer advantage of high deposition rates, which is important for high throughput. Using highly-polished substrates produced in a reel-to-reel polishing facility and buffer layers deposited in a pilot ion beam assisted deposition facility, meter-long second-generation high temperature superconductor tapes have been produced. 100 A class, meter-long coated conductor tapes have been reproducibly demonstrated in this work by both MOCVD and PLD. The best results to date are 148 A over 1.06 m by MOCVD and 135 A over 1.1 m by PLD using industrial laser.

Health Risk Evaluations for Ingestion Exposure of Humans to Polonium-210

PubMed Central

Scott, Bobby R.

2007-01-01

The incident in London during November 2006 involving a lethal intake by Mr. Alexander Litvinenko of the highly-radioactive, alpha-particles-emitting polonium-210 (Po-210) isotope, presumably via ingestion, sparked renewed interest in the area of Po-210 toxicity to humans. This paper is the result of assembling and interpreting existing Po-210 data within the context of what is considered a reliable risk model (hazard-function [HF] model) for characterizing the risk of death from deterministic effects of high alpha radiation doses and dose rates to body organs. The HF model was developed to address radiation exposure scenarios involving combined exposures to alpha, beta, and gamma radiations and can be used in circumstances where only one type of radiation is involved. Under a plausible but not yet validated set of assumptions and using available megabecquerel (Po-210) to gray dose-conversion factors, acute lethality risk vs. dose curves were developed for circumstances of ingestion exposure to Po-210 by humans. Initial risk calculations were carried out for a reference adult male human (a hypothetical 70-kg person). Results were then modified for application to all ages (except the in utero child) via the use of systemic Po-210 burden. Because of the unavailability of acute lethality data derived from human ingestions of high levels of Po-210, plausibility of risk calculations were evaluated based on data from studies of Po-210 injections in animals. The animal data, although limited, were found to be consistent with the theoretical risk calculations. Key findings are as follows: (1) ingestion (or inhalation) of a few tents of a milligram of Po-210 will likely be fatal to all exposed persons. (2) Lethal intakes are expected to involve fatal damage to the bone marrow which is likely to be compounded by damage caused by higher doses to other organs including the kidneys and liver. (3) Lethal intakes are expected to cause severe damage to the kidney, spleen, stomach, small and large intestines, lymph nodes, skin, and testes (males) in addition to the fatal damage to bone marrow. (4) The time distribution of deaths is expected to depend on the level of radioactivity ingested or inhaled, with deaths occurring within about a month after very high levels of radioactivity intake (e.g., systemic burdens > 1 MBq/kg-body-mass) and occurring over longer periods, possibly up to or exceeding a year for lower but lethal intakes (systemic burdens from 0.1 to 1.0 MBq/kg-body-mass). Below a systemic burden estimate of 0.02 MBq/kg-body-mass, deaths from deterministic effects are not expected to occur but the risk of cancer and for life shortening could be significant. New, funded experimental and modeling/theoretical research is needed to improve on these estimates. PMID:18648599

Elevated phospholipase D activity in androgen-insensitive prostate cancer cells promotes both survival and metastatic phenotypes.

PubMed

Utter, Matthew; Chakraborty, Sohag; Goren, Limor; Feuser, Lucas; Zhu, Yuan-Shan; Foster, David A

2018-06-01

Prostate cells are hormonally driven to grow and divide. Typical treatments for prostate cancer involve blocking activation of the androgen receptor by androgens. Androgen deprivation therapy can lead to the selection of cancer cells that grow and divide independently of androgen receptor activation. Prostate cancer cells that are insensitive to androgens commonly display metastatic phenotypes and reduced long-term survival of patients. In this study we provide evidence that androgen-insensitive prostate cancer cells have elevated PLD activity relative to the androgen-sensitive prostate cancer cells. PLD activity has been linked with promoting survival in many human cancer cell lines; and consistent with the previous studies, suppression of PLD activity in the prostate cancer cells resulted in apoptotic cell death. Of significance, suppressing the elevated PLD activity in androgen resistant prostate cancer lines also blocked the ability of these cells to migrate and invade Matrigel™. Since survival signals are generally an early event in tumorigenesis, the apparent coupling of survival and metastatic phenotypes implies that metastasis is an earlier event in malignant prostate cancer than generally thought. This finding has implications for screening strategies designed to identify prostate cancers before dissemination. Copyright © 2018 Elsevier B.V. All rights reserved.

Mobility enhancement in graphene transistors on low temperature pulsed laser deposited boron nitride

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uddin, Md Ahsan, E-mail: uddin2@email.sc.edu, E-mail: gkoley@clemson.edu; Koley, Goutam, E-mail: uddin2@email.sc.edu, E-mail: gkoley@clemson.edu; Department of Electrical Engineering, University of South Carolina, Columbia, South Carolina 29208

2015-11-16

Low temperature pulsed laser deposited (PLD) ultrathin boron nitride (BN) on SiO{sub 2} was investigated as a dielectric for graphene electronics, and a significant enhancement in electrical transport properties of graphene/PLD BN compared to graphene/SiO{sub 2} has been observed. Graphene synthesized by chemical vapor deposition and transferred on PLD deposited and annealed BN exhibited up to three times higher field effect mobility compared to graphene on the SiO{sub 2} substrate. Graphene field effect transistor devices fabricated on 5 nm BN/SiO{sub 2} (300 nm) yielded maximum hole and electron mobility of 4980 and 4200 cm{sup 2}/V s, respectively. In addition, significant improvement in carriermore » homogeneity and reduction in extrinsic doping in graphene on BN has been observed. An average Dirac point of 3.5 V and residual carrier concentration of 7.65 × 10{sup 11 }cm{sup −2} was observed for graphene transferred on 5 nm BN at ambient condition. The overall performance improvement on PLD BN can be attributed to dielectric screening of charged impurities, similar crystal structure and phonon modes, and reduced substrate induced doping.« less

[Detection and specific studies in procedural learning difficulties].

PubMed

Magallón, S; Narbona, J

2009-02-27

The main disabilities in non-verbal learning disorder (NLD) are: the acquisition and automating of motor and cognitive processes, visual spatial integration, motor coordination, executive functions, difficulty in comprehension of the context, and social skills. AIMS. To review the research to date on NLD, and to discuss whether the term 'procedural learning disorder' (PLD) would be more suitable to refer to NLD. A considerable amount of research suggests a neurological correlate of PLD with dysfunctions in the 'posterior' attention system, or the right hemisphere, or the cerebellum. Even if it is said to be difficult the delimitation between NLD and other disorders or syndromes like Asperger syndrome, certain characteristics contribute to differential diagnosis. Intervention strategies for the PLD must lead to the development of motor automatisms and problem solving strategies, including social skills. The basic dysfunction in NLD affects to implicit learning of routines, automating of motor skills and cognitive strategies that spare conscious resources in daily behaviours. These limitations are partly due to a dysfunction in non-declarative procedural memory. Various dimensions of language are also involved: context comprehension, processing of the spatial and emotional indicators of verbal language, language inferences, prosody, organization of the inner speech, use of language and non-verbal communication; this is why the diagnostic label 'PLD' would be more appropriate, avoiding the euphemistic adjective 'non-verbal'.

Beliefs and attitudes toward lethal management of deer in Cuyahoga Valley National Park

USGS Publications Warehouse

Fulton, D.C.; Skerl, K.; Shank, E.M.; Lime, D.W.

2004-01-01

We used the theory of reasoned action to help understand attitudes and beliefs about lethal management of deer (Odocoileus virginianus) in Cuyahoga Valley National Park (CVNP), Ohio. We used a mail-back survey to collect data from Ohio residents in the surrounding 9-county area. Two strata were defined: residents <10 km from CVNP (near n = 369) and residents =10 km from CVNP (far n = 312). Respondents indicated that lethal control of deer was acceptable (near 71%??4.7%, far 62%??5.5%) and taking no action to reduce deer populations was unacceptable (near 75%??4.5%, far 72%??5.1%). Beliefs about outcomes of lethal control and evaluation of those outcomes proved to be strong predictors of the acceptability of lethal control of deer in CVNP. Lethal control was more acceptable if it was done to prevent severe consequences for humans (e.g., spread of disease, car collisions) or the natural environment (e.g., maintain a healthy deer herd) than to prevent negative aesthetic impacts or personal property damage. Results from the study can be used to assist managers at CVNP as they make decisions regarding alternatives for deer management in the park and to inform others managing abundant deer populations of socially relevant impacts of management actions.

Fasting protects mice from lethal DNA damage by promoting small intestinal epithelial stem cell survival.

PubMed

Tinkum, Kelsey L; Stemler, Kristina M; White, Lynn S; Loza, Andrew J; Jeter-Jones, Sabrina; Michalski, Basia M; Kuzmicki, Catherine; Pless, Robert; Stappenbeck, Thaddeus S; Piwnica-Worms, David; Piwnica-Worms, Helen

2015-12-22

Short-term fasting protects mice from lethal doses of chemotherapy through undetermined mechanisms. Herein, we demonstrate that fasting preserves small intestinal (SI) architecture by maintaining SI stem cell viability and SI barrier function following exposure to high-dose etoposide. Nearly all SI stem cells were lost in fed mice, whereas fasting promoted sufficient SI stem cell survival to preserve SI integrity after etoposide treatment. Lineage tracing demonstrated that multiple SI stem cell populations, marked by Lgr5, Bmi1, or HopX expression, contributed to fasting-induced survival. DNA repair and DNA damage response genes were elevated in SI stem/progenitor cells of fasted etoposide-treated mice, which importantly correlated with faster resolution of DNA double-strand breaks and less apoptosis. Thus, fasting preserved SI stem cell viability as well as SI architecture and barrier function suggesting that fasting may reduce host toxicity in patients undergoing dose intensive chemotherapy.

PLD of metal insulator and relaxor electroceramic thin films

NASA Astrophysics Data System (ADS)

Bowman, Robert M.; Catalan, Gustau; Corbett, Michael H.; O'Neill, Dierdre; Gregg, J. M.

2001-04-01

In this paper we describe the use of pulsed laser deposition (PLD) for the growth of thin film VxOy, NdNiO3 and Pb(Mg1/3Nb2/3)O3. We begin by briefly describing our growth system. By showing case studies of the three materials systems we identify some important aspects and conditions that we believe are of crucial importance to oxide film growth in general.

Phosphatase-Resistant Analogues of Lysophosphatidic Acid

PubMed Central

Prestwich, Glenn D.; Gajewiak, Joanna; Zhang, Honglu; Xu, Xiaoyu; Yang, Guanghui; Serban, Monica

2008-01-01

Isoform-selective agonists and antagonists of the lysophosphatidic acid (LPA) G protein coupled receptors (GPCRs) have important potential applications in cell biology and therapy. LPA GPCRs regulate cancer cell proliferation, invasion, angiogenesis, and also biochemical resistance to chemotherapy- and radiotherapy-induced apoptosis. LPA and its analogues also are feedback inhibitors of the enzyme lysophospholipase D (lysoPLD, a.k.a., autotaxin, ATX), a central regulator of invasion and metastasis. For cancer therapy, the optimal therapeutic profile would be a metabolically stabilized, pan-LPA receptor antagonist that also inhibited lysoPLD. For protection of gastrointestinal mucosa and lymphocytes, LPA agonists would be desirable to minimize or reverse radiation or chemical-induced injury. Analogues of lysophosphatidic acid (LPA) that are chemically modified to be less susceptible to phospholipases and phosphatases show activity as long-lived receptor-specific agonists and antagonists for LPA receptors, as well as inhibitors for the lysoPLD activity of ATX. PMID:18454946

Continuous composition-spread thin films of transition metal oxides by pulsed-laser deposition

NASA Astrophysics Data System (ADS)

Ohkubo, I.; Christen, H. M.; Khalifah, P.; Sathyamurthy, S.; Zhai, H. Y.; Rouleau, C. M.; Mandrus, D. G.; Lowndes, D. H.

2004-02-01

We have designed an improved pulsed-laser deposition-continuous composition-spread (PLD-CCS) system that overcomes the difficulties associated with earlier related techniques. Our new PLD-CCS system is based on a precisely controlled synchronization between the laser firing, target exchange, and substrate translation/rotation, and offers more flexibility and control than earlier PLD-based approaches. Most importantly, the deposition energetics and the film thickness are kept constant across the entire composition range, and the resulting samples are sufficiently large to allow characterization by conventional techniques. We fabricated binary alloy composition-spread films composed of SrRuO 3 and CaRuO 3. Alternating ablation from two different ceramic targets leads to in situ alloy formation, and the value of x in Sr xCa x-1 RuO 3 can be changed linearly from 0 to 1 (or over any arbitrarily smaller range) along one direction of the substrate.

Fabrication of organic-inorganic perovskite thin films for planar solar cells via pulsed laser deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, Yangang; Zhang, Xiaohang; Gong, Yunhui

2016-01-15

We report on fabrication of organic-inorganic perovskite thin films using a hybrid method consisting of pulsed laser deposition (PLD) of lead iodide and spin-coating of methylammonium iodide. Smooth and highly crystalline CH{sub 3}NH{sub 3}PbI{sub 3} thin films have been fabricated on silicon and glass coated substrates with fluorine doped tin oxide using this PLD-based hybrid method. Planar perovskite solar cells with an inverted structure have been successfully fabricated using the perovskite films. Because of its versatility, the PLD-based hybrid fabrication method not only provides an easy and precise control of the thickness of the perovskite thin films, but also offersmore » a straightforward platform for studying the potential feasibility in using other metal halides and organic salts for formation of the organic-inorganic perovskite structure.« less

Scarp within Chasma Boreale

NASA Technical Reports Server (NTRS)

2006-01-01

This HiRISE image is of the north polar layered deposits (PLD) and underlying units exposed along the margins of Chasma Boreale. Chasma Boreale is the largest trough in the north PLD, thought to have formed due to outflow of water from underneath the polar cap, or due to winds blowing off the polar cap, or a combination of both. At the top and left of the image, the bright area with uniform striping is the gently sloping surface of the PLD. In the middle of the image this surface drops off in a steeper scarp, or cliff. At the top of this cliff we see the bright PLD in a side view, or cross-section. From these two perspectives of the PLD it is evident that the PLD are a stack of roughly horizontal layers. The gently sloping top surface cuts through the vertical sequence of layers at a low angle, apparently stretching the layers out horizontally and thus revealing details of the brightness and texture of individual layers. The surface of the PLD on the scarp is also criss-crossed by fine scale fractures. The layers of the PLD are probably composed of differing proportions of ice and dust, believed to be related to the climate conditions at the time they were deposited. In this way, sequences of polar layers are records of past climates on Mars, as ice cores from terrestrial ice sheets hold evidence of past climates on Earth. Further down the scarp in the center of the image the bright layers give way suddenly to a much darker section where a few layers are visible intermittently amongst aprons of dark material. The darkest material, with a smooth surface suggestive of loose grains, is thought to be sandy because similar exposures elsewhere show it to be formed into dunes by the wind. An intermediate-toned material also appears to form aprons draped over layers in the scarp, but its surface contains lobate structures that appear hardened into place and its edges are more abrupt in places, suggesting it may contain some ice or other cementing agent that makes it more competent, or resistant. At the base of the cliff, especially visible on the right side of the image, are several prominent bright layers with regular, rectangular-shaped polygons. Due to similarities in brightness and surface fracturing with the upper PLD, these bottom layers are also likely to be ice rich. The presence of sandy material sandwiched in between the upper PLD and these bottom layers suggests that the climate was once much different from the times during which the icier layers were deposited. The scattered bright and dark points are boulder-sized blocks that are likely pieces of the fractured PLD or other darker layers that have broken off and fallen downhill. At the bottom and right of the image, the floor of Chasma Boreale is dark, with a knobby texture and irregular polygons. Several circular features surrounded by an area that is slightly smoother, lighter, and raised relative to the chasm floor may be impact craters that have been modified after their formation in ice-rich ground.

Image PSP_001412_2650 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on November 14, 2006. The complete image is centered at 84.7 degrees latitude, 4.0 degrees East longitude. The range to the target site was 320.9 km (200.6 miles). At this distance the image scale ranges from 32.1 cm/pixel (with 1 x 1 binning) to 128.4 cm/pixel (with 4 x 4 binning). The image shown here has been map-projected to 25 cm/pixel. The image was taken at a local Mars time of 12:52 PM and the scene is illuminated from the west with a solar incidence angle of 67 degrees, thus the sun was about 23 degrees above the horizon. At a solar longitude of 135.3 degrees, the season on Mars is Northern Summer.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.

Acute systemic DNA damage in youth does not impair immune defense with aging.

PubMed

Pugh, Jason L; Foster, Sarah A; Sukhina, Alona S; Petravic, Janka; Uhrlaub, Jennifer L; Padilla-Torres, Jose; Hayashi, Tomonori; Nakachi, Kei; Smithey, Megan J; Nikolich-Žugich, Janko

2016-08-01

Aging-related decline in immunity is believed to be the main driver behind decreased vaccine efficacy and reduced resistance to infections in older adults. Unrepaired DNA damage is known to precipitate cellular senescence, which was hypothesized to be the underlying cause of certain age-related phenotypes. Consistent with this, some hallmarks of immune aging were more prevalent in individuals exposed to whole-body irradiation (WBI), which leaves no anatomical repository of undamaged hematopoietic cells. To decisively test whether and to what extent WBI in youth will leave a mark on the immune system as it ages, we exposed young male C57BL/6 mice to sublethal WBI (0.5-4 Gy), mimicking human survivor exposure during nuclear catastrophe. We followed lymphocyte homeostasis thorough the lifespan, response to vaccination, and ability to resist lethal viral challenge in the old age. None of the irradiated groups showed significant differences compared with mock-irradiated (0 Gy) animals for the parameters measured. Even the mice that received the highest dose of sublethal WBI in youth (4 Gy) exhibited equilibrated lymphocyte homeostasis, robust T- and B-cell responses to live attenuated West Nile virus (WNV) vaccine and full survival following vaccination upon lethal WNV challenge. Therefore, a single dose of nonlethal WBI in youth, resulting in widespread DNA damage and repopulation stress in hematopoietic cells, leaves no significant trace of increased immune aging in a lethal vaccine challenge model. © 2016 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Tumor-volume simulation during radiotherapy for head-and-neck cancer using a four-level cell population model.

PubMed

Chvetsov, Alexei V; Dong, Lei; Palta, Jantinder R; Amdur, Robert J

2009-10-01

To develop a fast computational radiobiologic model for quantitative analysis of tumor volume during fractionated radiotherapy. The tumor-volume model can be useful for optimizing image-guidance protocols and four-dimensional treatment simulations in proton therapy that is highly sensitive to physiologic changes. The analysis is performed using two approximations: (1) tumor volume is a linear function of total cell number and (2) tumor-cell population is separated into four subpopulations: oxygenated viable cells, oxygenated lethally damaged cells, hypoxic viable cells, and hypoxic lethally damaged cells. An exponential decay model is used for disintegration and removal of oxygenated lethally damaged cells from the tumor. We tested our model on daily volumetric imaging data available for 14 head-and-neck cancer patients treated with an integrated computed tomography/linear accelerator system. A simulation based on the averaged values of radiobiologic parameters was able to describe eight cases during the entire treatment and four cases partially (50% of treatment time) with a maximum 20% error. The largest discrepancies between the model and clinical data were obtained for small tumors, which may be explained by larger errors in the manual tumor volume delineation procedure. Our results indicate that the change in gross tumor volume for head-and-neck cancer can be adequately described by a relatively simple radiobiologic model. In future research, we propose to study the variation of model parameters by fitting to clinical data for a cohort of patients with head-and-neck cancer and other tumors. The potential impact of other processes, like concurrent chemotherapy, on tumor volume should be evaluated.

The genotoxic effects of the imidacloprid-based insecticide formulation Glacoxan Imida on Montevideo tree frog Hypsiboas pulchellus tadpoles (Anura, Hylidae).

PubMed

Pérez-Iglesias, J M; Ruiz de Arcaute, C; Nikoloff, N; Dury, L; Soloneski, S; Natale, G S; Larramendy, M L

2014-06-01

The neonicotinoid insecticide imidacloprid (IMI) affects the insect central nervous system and is successfully applied to control pests for a variety of agricultural crops. In the current study, acute toxicity and genotoxicity of the IMI-containing commercial formulation insecticide Glacoxan Imida (35 percent IMI) was evaluated on Hypsiboas pulchellus (Anura: Hylidae) tadpoles exposed under laboratory conditions. A lethal effect was evaluated as the end point for lethality, whereas micronucleus (MN) frequency and DNA single-strand breaks evaluated by the single cell gel electrophoresis (SCGE) assay were employed as end points for genotoxicity. Sublethal end points were assayed within the 12.5-37.5mg/L IMI concentration range. Experiments were performed on tadpoles at stage 36 (range, 35-37) according to the classification proposed by Gosner. Lethality studies revealed an LC50 96h value of 52.622mg/L IMI. Increased frequency of MNs was only observed when 25.0mg/L was assayed for 96h, whereas no other nuclear abnormalities were induced. Increase of the genetic damage index was observed at 48h of treatment within the 12.5-37.5mg/L concentration range, whereas an increased frequency of DNA damage was observed only in tadpoles treated with 37.5mg/L IMI for 96h. This study represents the first evidence of the acute lethal and genotoxic effects exerted by IMI on tadpoles of an amphibian species native to Argentina under laboratory conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

Chronic Exposure of Corals to Fine Sediments: Lethal and Sub-Lethal Impacts

PubMed Central

Flores, Florita; Hoogenboom, Mia O.; Smith, Luke D.; Cooper, Timothy F.; Abrego, David; Negri, Andrew P.

2012-01-01

Understanding the sedimentation and turbidity thresholds for corals is critical in assessing the potential impacts of dredging projects in tropical marine systems. In this study, we exposed two species of coral sampled from offshore locations to six levels of total suspended solids (TSS) for 16 weeks in the laboratory, including a 4 week recovery period. Dose-response relationships were developed to quantify the lethal and sub-lethal thresholds of sedimentation and turbidity for the corals. The sediment treatments affected the horizontal foliaceous species (Montipora aequituberculata) more than the upright branching species (Acropora millepora). The lowest sediment treatments that caused full colony mortality were 30 mg l−1 TSS (25 mg cm−2 day−1) for M. aequituberculata and 100 mg l−1 TSS (83 mg cm−2 day−1) for A. millepora after 12 weeks. Coral mortality generally took longer than 4 weeks and was closely related to sediment accumulation on the surface of the corals. While measurements of damage to photosystem II in the symbionts and reductions in lipid content and growth indicated sub-lethal responses in surviving corals, the most reliable predictor of coral mortality in this experiment was long-term sediment accumulation on coral tissue. PMID:22662225

Effects of β-glucan polysaccharide revealed by the dominant lethal assay and micronucleus assays, and reproductive performance of male mice exposed to cyclophosphamide

PubMed Central

Oliveira, Rodrigo Juliano; Pesarini, João Renato; Sparça Salles, Maria José; Nakamura Kanno, Tatiane Yumi; dos Santos Lourenço, Ana Carolina; da Silva Leite, Véssia; da Silva, Ariane Fernanda; Matiazi, Hevenilton José; Ribeiro, Lúcia Regina; Mantovani, Mário Sérgio

2014-01-01

β-glucan is a well-known polysaccharide for its chemopreventive effect. This study aimed to evaluate the chemopreventive ability of β-glucan in somatic and germ cells through the dominant lethal and micronucleus assays, and its influence on the reproductive performance of male mice exposed to cyclophosphamide. The results indicate that β-glucan is capable of preventing changes in DNA in both germ cells and somatic ones. Changes in germ cells were evaluated by the dominant lethal assay and showed damage reduction percentages of 46.46% and 43.79% for the doses of 100 and 150 mg/kg. For the somatic changes, evaluated by micronucleus assay in peripheral blood cells in the first week of treatment, damage reduction percentages from 80.63–116.32% were found. In the fifth and sixth weeks, the percentage ranged from 10.20–52.54% and −0.95–62.35%, respectively. Besides the chemopreventive efficiency it appears that the β-glucan, when combined with cyclophosphamide, is able to improve the reproductive performance of males verified by the significant reduction in rates of post-implantation losses and reabsorption in the mating of nulliparous females with males treated with cyclophosphamide. PMID:24688298

Effects of β-glucan polysaccharide revealed by the dominant lethal assay and micronucleus assays, and reproductive performance of male mice exposed to cyclophosphamide.

PubMed

Oliveira, Rodrigo Juliano; Pesarini, João Renato; Sparça Salles, Maria José; Nakamura Kanno, Tatiane Yumi; Dos Santos Lourenço, Ana Carolina; da Silva Leite, Véssia; da Silva, Ariane Fernanda; Matiazi, Hevenilton José; Ribeiro, Lúcia Regina; Mantovani, Mário Sérgio

2014-03-01

β-glucan is a well-known polysaccharide for its chemopreventive effect. This study aimed to evaluate the chemopreventive ability of β-glucan in somatic and germ cells through the dominant lethal and micronucleus assays, and its influence on the reproductive performance of male mice exposed to cyclophosphamide. The results indicate that β-glucan is capable of preventing changes in DNA in both germ cells and somatic ones. Changes in germ cells were evaluated by the dominant lethal assay and showed damage reduction percentages of 46.46% and 43.79% for the doses of 100 and 150 mg/kg. For the somatic changes, evaluated by micronucleus assay in peripheral blood cells in the first week of treatment, damage reduction percentages from 80.63-116.32% were found. In the fifth and sixth weeks, the percentage ranged from 10.20-52.54% and -0.95-62.35%, respectively. Besides the chemopreventive efficiency it appears that the β-glucan, when combined with cyclophosphamide, is able to improve the reproductive performance of males verified by the significant reduction in rates of post-implantation losses and reabsorption in the mating of nulliparous females with males treated with cyclophosphamide.

Technical report. The application of probability-generating functions to linear-quadratic radiation survival curves.

PubMed

Kendal, W S

2000-04-01

To illustrate how probability-generating functions (PGFs) can be employed to derive a simple probabilistic model for clonogenic survival after exposure to ionizing irradiation. Both repairable and irreparable radiation damage to DNA were assumed to occur by independent (Poisson) processes, at intensities proportional to the irradiation dose. Also, repairable damage was assumed to be either repaired or further (lethally) injured according to a third (Bernoulli) process, with the probability of lethal conversion being directly proportional to dose. Using the algebra of PGFs, these three processes were combined to yield a composite PGF that described the distribution of lethal DNA lesions in irradiated cells. The composite PGF characterized a Poisson distribution with mean, chiD+betaD2, where D was dose and alpha and beta were radiobiological constants. This distribution yielded the conventional linear-quadratic survival equation. To test the composite model, the derived distribution was used to predict the frequencies of multiple chromosomal aberrations in irradiated human lymphocytes. The predictions agreed well with observation. This probabilistic model was consistent with single-hit mechanisms, but it was not consistent with binary misrepair mechanisms. A stochastic model for radiation survival has been constructed from elementary PGFs that exactly yields the linear-quadratic relationship. This approach can be used to investigate other simple probabilistic survival models.

Outcomes with single agent LIPO-DOX in platinum-resistant ovarian and fallopian tube cancers and primary peritoneal adenocarcinoma - Chiang Mai University Hospital experience.

PubMed

Suprasert, Prapaporn; Manopunya, Manatsawee; Cheewakriangkrai, Chalong

2014-01-01

Single pegylated liposomal doxorubicin (PLD) is commonly used as a salvage treatment in platinum-resistant ovarian cancer, fallopian tube cancer and primary peritoneal adenocarcinoma (PPA) with a satisfactory outcome. However, the data for second generation PLD administered in this setting are still limited. We conducted a retrospective study to evaluate the outcome of patients who received single-agent second generation PLD (LIPO-DOX) after the development of clinical platinum resistance. The study period was between March 2008 and March 2013. LIPO-DOX was administered intravenously 40 mg/m2 every 28 days until disease progression, but for not more than six cycles. The response rate was evaluated using the Gynecologic Cancer Intergroup (GCIG) criteria while the toxicity was evaluated according to WHO criteria. Twenty-nine patients met the inclusion criteria in the study period with an overall response rate of 13.8%. The median progression free survival and overall survival were three and eleven months, respectively. With the total of 96 cycles of chemotherapy, the patients developed grades 3 and 4 hematologic toxicity as follows: anemia, 0%, leukopenia, 9.6%, neutropenia, 32.3% and thrombocytopenia, 0%. In conclusion, the single agent second generation PLD demonstrated modest efficacy in patients with platinum-resistant ovarian cancer, fallopian tube cancer and PPA without serious toxicity.

A new approach to epitaxially grow high-quality GaN films on Si substrates: the combination of MBE and PLD.

PubMed

Wang, Wenliang; Wang, Haiyan; Yang, Weijia; Zhu, Yunnong; Li, Guoqiang

2016-04-22

High-quality GaN epitaxial films have been grown on Si substrates with Al buffer layer by the combination of molecular beam epitaxy (MBE) and pulsed laser deposition (PLD) technologies. MBE is used to grow Al buffer layer at first, and then PLD is deployed to grow GaN epitaxial films on the Al buffer layer. The surface morphology, crystalline quality, and interfacial property of as-grown GaN epitaxial films on Si substrates are studied systematically. The as-grown ~300 nm-thick GaN epitaxial films grown at 850 °C with ~30 nm-thick Al buffer layer on Si substrates show high crystalline quality with the full-width at half-maximum (FWHM) for GaN(0002) and GaN(102) X-ray rocking curves of 0.45° and 0.61°, respectively; very flat GaN surface with the root-mean-square surface roughness of 2.5 nm; as well as the sharp and abrupt GaN/AlGaN/Al/Si hetero-interfaces. Furthermore, the corresponding growth mechanism of GaN epitaxial films grown on Si substrates with Al buffer layer by the combination of MBE and PLD is hence studied in depth. This work provides a novel and simple approach for the epitaxial growth of high-quality GaN epitaxial films on Si substrates.

A pharmacological screen for compounds that rescue the developmental lethality of a Drosophila ATM mutant.

PubMed

Rimkus, Stacey A; Wassarman, David A

2018-01-01

Ataxia-telangiectasia (A-T) is a neurodegenerative disease caused by mutation of the A-T mutated (ATM) gene. ATM encodes a protein kinase that is activated by DNA damage and phosphorylates many proteins, including those involved in DNA repair, cell cycle control, and apoptosis. Characteristic biological and molecular functions of ATM observed in mammals are conserved in Drosophila melanogaster. As an example, conditional loss-of-function ATM alleles in flies cause progressive neurodegeneration through activation of the innate immune response. However, unlike in mammals, null alleles of ATM in flies cause lethality during development. With the goals of understanding biological and molecular roles of ATM in a whole animal and identifying candidate therapeutics for A-T, we performed a screen of 2400 compounds, including FDA-approved drugs, natural products, and bioactive compounds, for modifiers of the developmental lethality caused by a temperature-sensitive ATM allele (ATM8) that has reduced kinase activity at non-permissive temperatures. Ten compounds reproducibly suppressed the developmental lethality of ATM8 flies, including Ronnel, which is an organophosphate. Ronnel and other suppressor compounds are known to cause mitochondrial dysfunction or to inhibit the enzyme acetylcholinesterase, which controls the levels of the neurotransmitter acetylcholine, suggesting that detrimental consequences of reduced ATM kinase activity can be rescued by inhibiting the function of mitochondria or increasing acetylcholine levels. We carried out further studies of Ronnel because, unlike the other compounds that suppressed the developmental lethality of homozygous ATM8 flies, Ronnel was toxic to the development of heterozygous ATM8 flies. Ronnel did not affect the innate immune response of ATM8 flies, and it further increased the already high levels of DNA damage in brains of ATM8 flies, but its effects were not harmful to the lifespan of rescued ATM8 flies. These results provide new leads for understanding the biological and molecular roles of ATM and for the treatment of A-T.

[An investigation on self-harm episodes and their relationship with suicidal psychology and behaviors in 2713 college students].

PubMed

Su, Pu-Yu; Hao, Jia-Hu; Huang, Zhao-Hui; Tao, Fang-Biao

2010-11-01

To investigate the episodes and influencing factors on self-harm and to explore the relationship between self-harm episodes and suicidal psychology and behaviors in college students. Four universities were selected using cluster sampling method in Anqing city and Chaohu city. Totally, 2713 college students completed this survey. Data were analyzed by Pearson Chi-square and logistic regression. In the last six months, rates of highly lethal self-harm, less lethal self-harm with visible tissue damage, self-injury without visible tissue damage, self-harmful behaviors with latency damage, other self-harmful behaviors with menticide were 1.9%, 5.5%, 15.3%, 21.2% and 17.0% respectively. The total rate of self-harm was 31.3%. 73.1% of the students with self harmful experiences had the above mentioned behaviors more than 3 times in the last six months. The top 3 reasons for taking self-harm actions were: having learning problems (43.1%), failed love affairs (25.0%) and having conflicts with others (23.9%). There were different influencing factors among different kinds of self-harm episodes. Depression was the risk factor of self-harm. The higher score of having high self-esteem was the protective factor of all kinds of self-harm actions except highly lethal ones. Higher score of difficulties in identifying feelings was one of the risk factors. The rates of suicidal psychology and behaviors in students with self-harm were significantly higher than those in students without those behaviors. Result from linear χ(2) test indicated that the graveness of tissue damage of self-harm was higher along with the rates of suicidal psychology and behaviors (P < 0.01). Among 2713 college students, about 1/3 adolescents having experienced self-harm in the last 6 months, many with repeated ones. Depression and difficulties in identifying feelings were the two risk factors while self-esteem was the protective factor related to most of the self-harm cases.

The role of proximal body information on anticipatory judgment in tennis using graphical information richness

PubMed Central

Ida, Hirofumi; Ogata, Takahiro; Ishii, Motonobu; Higuchi, Takahiro

2017-01-01

Objective Recent studies have reported that skilled tennis players are likely to use proximal body information for anticipating the direction of their opponent’s forehand shot. However, in these studies, the visual stimuli did not include visual information about the ball. Skilled players may have used proximal information owing to the lack of distal information. To address this issue, we developed a novel methodological approach using computer graphics (CG) images in which the entire body was presented by a combination of point-light display (i.e., poor graphical information, PLD) and polygons (i.e., rich graphical information). Using our novel methodological approach, we examined whether skilled tennis players use proximal body information when anticipating shot directions. Methods and results Fifteen skilled tennis players and fifteen novice players tried to anticipate shot directions by observing four CG forehand strokes (ALPOL: all body parts were represented with polygon; RAPLD: racket and arm were represented with PLD; BOPLD: body parts without racket and arm were represented with PLD; and ALPLD: all body parts were represented with PLD). Our intention in creating CG models with such combinations (i.e., RAPLD and BOPLD) was that because of the richer graphical information provided by polygons compared to PLD, the participant’s anticipatory judgment would be influenced more by body parts expressed with polygons. The results showed that for skilled players, anticipatory judgment was more accurate when they observed RAPLD than when they observed BOPLD and ALPLD. In contrast, for novice players, there were no differences in the accuracy of anticipatory judgments with the four CG models. Conclusions Only skilled players made more accurate anticipatory judgments when body regions were expressed with rich graphical information, and the racket and arm were expressed with poor graphical information. These suggest that skilled players used proximal information to effectively anticipate shot directions. PMID:28704485

A novel mixed phospholipid functionalized monolithic column for early screening of drug induced phospholipidosis risk.

PubMed

Zhao, XiangLong; Chen, WeiJia; Liu, ZhengHua; Guo, JiaLiang; Zhou, ZhengYin; Crommen, Jacques; Moaddel, Ruin; Jiang, ZhengJin

2014-11-07

Drug-induced phospholipidosis (PLD) is characterized by the excessive accumulation of phospholipids, resulting in multilamellar vesicle structure within lysosomes. In the present study, a novel mixed phospholipid functionalized monolithic column was developed for the first time through a facile one-step co-polymerization approach. The phospholipid composition of the monolith can be adjusted quantitatively and accurately to mimic the mixed phospholipid environment of different biomembranes on a solid matrix. The mixed phospholipid functionalized monolith as a promising immobilized artificial membrane technique was used to study drug-phospholipid interaction. Scanning electron microscopy, elemental analysis, FT-IR spectra, ζ-potential analysis and micro-HPLC were carried out to characterize the physicochemical properties and separation performance of the monolith. Mechanism studies revealed that both hydrophobic and electrostatic interactions play an important role in the retention of analytes. The ratio of their contributions to retention can be easily manipulated by adjusting the composition of the mixed phospholipids, in order to better mimic the interaction between drugs and cell membrane. The obtained mixed phospholipid functionalized monolithic columns were applied to the screening of drug-induced PLD potency. Data from 79 drugs on the market demonstrated that the chromatographic hydrophobicity index referring to the mixed phospholipid functionalized monolith at pH 7.4 (CHI IAM7.4) for the selected drugs were highly correlated with the drug-induced PLD potency data obtained from other in vivo or in vitro assays. Moreover, the effect of the acidic phospholipid phosphatidylserine proportion on prediction accuracy was also investigated. The monolith containing 20% phosphatidylserine and 80% phosphatidylcholine exhibited the best prediction ability for the drug-induced PLD potency of the tested compounds. This research has led to the successful development of a novel and facile approach to prepare a mixed phospholipids functionalized monolith, which offers a reliable, cost-effective and high-throughput screening tool for early prediction of the PLD potency of drug candidates. Copyright © 2014 Elsevier B.V. All rights reserved.

Switching of dominant retrotransposon silencing strategies from posttranscriptional to transcriptional mechanisms during male germ-cell development in mice

PubMed Central

Inoue, Kota; Fukuda, Kei; Sasaki, Hiroyuki

2017-01-01

Mammalian genomes harbor millions of retrotransposon copies, some of which are transpositionally active. In mouse prospermatogonia, PIWI-interacting small RNAs (piRNAs) combat retrotransposon activity to maintain the genomic integrity. The piRNA system destroys retrotransposon-derived RNAs and guides de novo DNA methylation at some retrotransposon promoters. However, it remains unclear whether DNA methylation contributes to retrotransposon silencing in prospermatogonia. We have performed comprehensive studies of DNA methylation and polyA(+) RNAs (transcriptome) in developing male germ cells from Pld6/Mitopld and Dnmt3l knockout mice, which are defective in piRNA biogenesis and de novo DNA methylation, respectively. The Dnmt3l mutation greatly reduced DNA methylation levels at most retrotransposons, but its impact on their RNA abundance was limited in prospermatogonia. In Pld6 mutant germ cells, although only a few retrotransposons exhibited reduced DNA methylation, many showed increased expression at the RNA level. More detailed analysis of RNA sequencing, nascent RNA quantification, profiling of cleaved RNA ends, and the results obtained from double knockout mice suggest that PLD6 works mainly at the posttranscriptional level. The increase in retrotransposon expression was larger in Pld6 mutants than it was in Dnmt3l mutants, suggesting that RNA degradation by the piRNA system plays a more important role than does DNA methylation in prospermatogonia. However, DNA methylation had a long-term effect: hypomethylation caused by the Pld6 or Dnmt3l mutation resulted in increased retrotransposon expression in meiotic spermatocytes. Thus, posttranscriptional silencing plays an important role in the early stage of germ cell development, then transcriptional silencing becomes important in later stages. In addition, intergenic and intronic retrotransposon sequences, in particular those containing the antisense L1 promoters, drove ectopic expression of nearby genes in both mutant spermatocytes, suggesting that retrotransposon silencing is important for the maintenance of not only genomic integrity but also transcriptomic integrity. PMID:28749988

SINGLE AGENT CARBOPLATIN VERSUS CARBOPLATIN PLUS PEGYLATED LIPOSOMAL DOXORUBICIN IN RECURRENT OVARIAN CANCER: FINAL SURVIVAL RESULTS OF A SWOG (S0200) PHASE 3 RANDOMIZED TRIAL

PubMed Central

Markman, Maurie; Moon, James; Wilczynski, Sharon; Lopez, Ana Maria; Rowland, Kendrith M.; Michelin, David P.; Lanzotti, Victor J.; Anderson, Garnet L.; Alberts, David S.

2009-01-01

Objectives Randomized phase 3 trials have demonstrated the utility of a regimen of carboplatin plus pegylated liposomal doxorubicin (PLD) in recurrent ovarian cancer, and have provided provocative data suggesting a substantially lower risk of carboplatin-associated hypersensitivity if PDL is delivered in combination with the platinum agent. Methods To further examine both of these clinically-relevant issues, the survival outcome (with longer follow-up) and hypersensitivity reaction profile of a previously reported phase 3 trial that compared single agent carboplatin (AUC 5) to carboplatin (AUC 5) plus PLD (30 mg/m2) delivered on an every 4-week schedule in recurrent ovarian cancer (SWOG 0200) were re-analyzed. Results In the limited number of patients (n=61) entered into this phase 3 study before closure by the SWOG Data Safety and Monitoring Committee due to insufficient accrual, there was an initially reported improvement in outcome associated with the combination regimen. With longer follow-up and additional events there is still a statistically-significant improved progression-free survival (median: 12 versus 8 months, p=0.02), but the previously observed impact of the two-drug regimen on overall survival is no longer apparent (median: 31 versus 18 months; p=0.2). While no hypersensitivity reactions were reported in the carboplatin plus PLD arm (0/31), 9 of 30 patients (30%) of women randomized to single agent carboplatin experienced an allergic episode (p=0.0008), with 5 being ≥ grade 3 in severity. Conclusion Despite a favorable impact of carboplatin and PLD on progression-free survival in this trial, the effect on overall survival is not statistically significant. For currently unknown reasons, administering PLD with carboplatin appears to substantially reduce the incidence of platinum-associated hypersensitivity reactions. PMID:20044128

Arterial Transit Time-corrected Renal Blood Flow Measurement with Pulsed Continuous Arterial Spin Labeling MR Imaging.

PubMed

Shimizu, Kazuhiro; Kosaka, Nobuyuki; Fujiwara, Yasuhiro; Matsuda, Tsuyoshi; Yamamoto, Tatsuya; Tsuchida, Tatsuro; Tsuchiyama, Katsuki; Oyama, Nobuyuki; Kimura, Hirohiko

2017-01-10

The importance of arterial transit time (ATT) correction for arterial spin labeling MRI has been well debated in neuroimaging, but it has not been well evaluated in renal imaging. The purpose of this study was to evaluate the feasibility of pulsed continuous arterial spin labeling (pcASL) MRI with multiple post-labeling delay (PLD) acquisition for measuring ATT-corrected renal blood flow (ATC-RBF). A total of 14 volunteers were categorized into younger (n = 8; mean age, 27.0 years) and older groups (n = 6; 64.8 years). Images of pcASL were obtained at three different PLDs (0.5, 1.0, and 1.5 s), and ATC-RBF and ATT were calculated using a single-compartment model. To validate ATC-RBF, a comparative study of effective renal plasma flow (ERPF) measured by 99m Tc-MAG3 scintigraphy was performed. ATC-RBF was corrected by kidney volume (ATC-cRBF) for comparison with ERPF. The younger group showed significantly higher ATC-RBF (157.68 ± 38.37 mL/min/100 g) and shorter ATT (961.33 ± 260.87 ms) than the older group (117.42 ± 24.03 mL/min/100 g and 1227.94 ± 226.51 ms, respectively; P < 0.05). A significant correlation was evident between ATC-cRBF and ERPF (P < 0.05, r = 0.47). With suboptimal single PLD (1.5 s) settings, there was no significant correlation between ERPF and kidney volume-corrected RBF calculated from single PLD data. Calculation of ATT and ATC-RBF by pcASL with multiple PLD was feasible in healthy volunteers, and differences in ATT and ATC-RBF were seen between the younger and older groups. Although ATT correction by multiple PLD acquisitions may not always be necessary for RBF quantification in the healthy subjects, the effect of ATT should be taken into account in renal ASL-MRI as debated in brain imaging.

Glycoxidation and inflammatory markers in patients on treatment with PMMA-based protein-leaking dialyzers.

PubMed

Galli, Francesco; Benedetti, Serena; Floridi, Ardesio; Canestrari, Franco; Piroddi, Marta; Buoncristiani, Emanuela; Buoncristiani, Umberto

2005-02-01

High-molecular-weight solutes such as glycation and oxidation protein products are putative proinflammatory mediators found in the uremic blood. The elimination of these and other large solutes by protein-leaking dialyzers (PLD) might help to correct the inflammatory status of maintenance hemodialysis (HD) patients. Two matched groups of 13 standard 3 times/week HD patients were treated for 6 months with PMMA-based PLD and non-protein-leaking dialyzers (NPLD), respectively. At baseline, 1, 3, and 6 months, we measured the blood levels of the inflammatory cytokines IL-1beta, TNF-alpha, IL-6, the acute-phase protein C-reactive protein (CRP), the adhesion molecules ICAM-1, VCAM-1, and selectine-E, the chemotaxis factors MCP-1, and the glycation and oxidation protein end products pentosidine, protein carbonyls, and AOPP. In all the patients at baseline, pre-HD levels of glycation and oxidation protein markers, and inflammatory parameters were significantly higher than in healthy control subjects (P < 0.01 or greater). After 6 months, in the group on treatment with PLD, but not in that on NPLD, there was a significant decrease (P < 0.05 or greater) of pre-HD values of total pentosidine (mainly represented by pentosidine in serum albumin; -43%), protein carbonyls (-42%), AOPP (-38%), and the inflammatory cytokines IL-1beta (-49%), IL-6 (-39%), and TNF-alpha (-20%), while IL-10 and INF-gamma increased by 67% and 37%, respectively. Proinflammatory cytokines, and particularly IL-6, showed a positive correlation with the levels of circulating pentosidine. Protidemia was not significantly modified at the end of the study in both the groups. The results in this pilot study show that the removal of large solutes by PLD can improve some indices of chronic inflammation in HD patients. Further studies are required to determine the relevance of the individual solutes removed with PLD as proinflammatory mediators in the uremic environment.

More human, more humane: a new approach for testing airborne pollutants.

PubMed

Potera, Carol

2007-03-01

People not only inhale airborne contaminants but also absorb them through the skin. Both routes can set off localized toxic reactions or damage internal organs such as the liver, kidney, and brain. Conventional tests of the toxicity of gases and vapors, in which laboratory animals are exposed to lethal or sub-lethal doses of chemicals, have been criticized as expensive, unethical, inhumane, and time-consuming. Now researchers at the University of New South Wales (UNSW) in Sydney, Australia, have developed an animal-free alternative that uses human cells to test the effects of exposure to airborne toxicants.

Silencing of human DNA polymerase λ causes replication stress and is synthetically lethal with an impaired S phase checkpoint

PubMed Central

Zucca, Elisa; Bertoletti, Federica; Wimmer, Ursula; Ferrari, Elena; Mazzini, Giuliano; Khoronenkova, Svetlana; Grosse, Nicole; van Loon, Barbara; Dianov, Grigory; Hübscher, Ulrich; Maga, Giovanni

2013-01-01

Human DNA polymerase (pol) λ functions in base excision repair and non-homologous end joining. We have previously shown that DNA pol λ is involved in accurate bypass of the two frequent oxidative lesions, 7,8-dihydro-8-oxoguanine and 1,2-dihydro-2-oxoadenine during the S phase. However, nothing is known so far about the relationship of DNA pol λ with the S phase DNA damage response checkpoint. Here, we show that a knockdown of DNA pol λ, but not of its close homologue DNA pol β, results in replication fork stress and activates the S phase checkpoint, slowing S phase progression in different human cancer cell lines. We furthermore show that DNA pol λ protects cells from oxidative DNA damage and also functions in rescuing stalled replication forks. Its absence becomes lethal for a cell when a functional checkpoint is missing, suggesting a DNA synthesis deficiency. Our results provide the first evidence, to our knowledge, that DNA pol λ is required for cell cycle progression and is functionally connected to the S phase DNA damage response machinery in cancer cells. PMID:23118481

[Assessment of impacts of combined treatment of solid urban waste landfill leachate and sewage on aquatic biota].

PubMed

Mannarino, Camille Ferreira; Moreira, Josino Costa; Ferreira, João Alberto; Arias, Ana Rosa Linde

2013-11-01

The impact on tilapia fish of combined treatment of landfill leachate and domestic sewage was monitored in a waste treatment plant that operated on a pilot scale using the activated sludge process. Biomarkers of sub-lethal toxicity were used to indicate the possibility of damage to organisms due to interaction with pollutants. The concentration of metallothioneins did not indicate the increased presence of metals in fish exposed than in control groups. Acetylcholinesterase enzyme activity was inhibited in only one of the exposed groups, indicating the possible presence of organophosphate and/or carbamate pesticides in treated effluent. The PAHs used as biomarkers (naphthalene, pyrene, benzo(a)pyrene and 1-hydroxypyrene) indicated that exposed fish had a greater absorption of PAHs than control groups of fish, indicating the likely presence of these compounds in at least one of the combined treatment effluents. The frequencies of micronuclei and other erythrocytic nuclear abnormalities also indicate greater genotoxic damage in cells of organisms exposed than in control groups. The use of biomarkers proved to be important to permit an evaluation of sub-lethal damage present in organisms exposed to the pollution source studied.

Ubiquitin facilitates a quality-control pathway that removes damaged chloroplasts

DOE PAGES

Woodson, Jesse D.; Joens, Matthew S.; Sinson, Andrew B.; ...

2015-10-23

Energy production by chloroplasts and mitochondria causes constant oxidative damage. A functioning photosynthetic cell requires quality-control mechanisms to turn over and degrade chloroplasts damaged by reactive oxygen species (ROS). Here in this study, we generated a conditionally lethal Arabidopsis mutant that accumulated excess protoporphyrin IX in the chloroplast and produced singlet oxygen. Damaged chloroplasts were subsequently ubiquitinated and selectively degraded. A genetic screen identified the plant U-box 4 (PUB4) E3 ubiquitin ligase as being necessary for this process. pub4-6 mutants had defects in stress adaptation and longevity. As a result, we have identified a signal that leads to the targetedmore » removal of ROS-overproducing chloroplasts.« less

Ubiquitin facilitates a quality-control pathway that removes damaged chloroplasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodson, Jesse D.; Joens, Matthew S.; Sinson, Andrew B.

Energy production by chloroplasts and mitochondria causes constant oxidative damage. A functioning photosynthetic cell requires quality-control mechanisms to turn over and degrade chloroplasts damaged by reactive oxygen species (ROS). Here in this study, we generated a conditionally lethal Arabidopsis mutant that accumulated excess protoporphyrin IX in the chloroplast and produced singlet oxygen. Damaged chloroplasts were subsequently ubiquitinated and selectively degraded. A genetic screen identified the plant U-box 4 (PUB4) E3 ubiquitin ligase as being necessary for this process. pub4-6 mutants had defects in stress adaptation and longevity. As a result, we have identified a signal that leads to the targetedmore » removal of ROS-overproducing chloroplasts.« less

Tissue responses to low protracted doses of high let radiations or photons - Early and late damage relevant to radio-protective countermeasures

NASA Technical Reports Server (NTRS)

Ainsworth, E. J.; Afzal, S. M. J.; Crouse, D. A.; Hanson, W. R.; Fry, R. J. M.

1989-01-01

Early and late murine tissue responses to single or fractionated low doses of heavy charged particles, fission-spectrum neutrons or gamma rays are considered. Damage to the hematopoietic system is emphasized, but results on acute lethality, host response to challenge with transplanted leukemia cells and life-shortening are presented. Recent studies on protection against early and late effects by aminothiols, prostaglandins, and other compounds are discussed.

An Oxygenated and Transportable Machine Perfusion System Fully Rescues Liver Grafts Exposed to Lethal Ischemic Damage in a Pig Model of DCD Liver Transplantation.

PubMed

Compagnon, Philippe; Levesque, Eric; Hentati, Hassen; Disabato, Mara; Calderaro, Julien; Feray, Cyrille; Corlu, Anne; Cohen, José Laurent; Ben Mosbah, Ismail; Azoulay, Daniel

2017-07-01

Control of warm ischemia (WI) lesions that occur with donation after circulatory death (DCD) would significantly increase the donor pool for liver transplantation. We aimed to determine whether a novel, oxygenated and hypothermic machine perfusion device (HMP Airdrive system) improves the quality of livers derived from DCDs using a large animal model. Cardiac arrest was induced in female large white pigs by intravenous injection of potassium chloride. After 60 minutes of WI, livers were flushed in situ with histidine-tryptophan-ketoglutarate and subsequently preserved either by simple cold storage (WI-SCS group) or HMP (WI-HMP group) using Belzer-MPS solution. Liver grafts procured from heart-beating donors and preserved by SCS served as controls. After 4 hours of preservation, all livers were transplanted. All recipients in WI-SCS group died within 6 hours after transplantation. In contrast, the HMP device fully protected the liver against lethal ischemia/reperfusion injury, allowing 100% survival rate. A postreperfusion syndrome was observed in all animals of the WI-SCS group but none of the control or WI-HMP groups. After reperfusion, HMP-preserved livers functioned better and showed less hepatocellular and endothelial cell injury, in agreement with better-preserved liver histology relative to WI-SCS group. In addition to improved energy metabolism, this protective effect was associated with an attenuation of inflammatory response, oxidative load, endoplasmic reticulum stress, mitochondrial damage, and apoptosis. This study demonstrates for the first time the efficacy of the HMP Airdrive system to protect liver grafts from lethal ischemic damage before transplantation in a clinically relevant DCD model.

Cathodoluminescence Study of Hafnium Oxide

NASA Astrophysics Data System (ADS)

Purcell, Emily; Hengehold, Robert; McClory, John

2011-10-01

Hafnium dioxide (HfO2) is increasingly being used in place of silicon oxide as a gate insulator in field effect transistors. This is primarily due to its high dielectric constant, κ, of 25. Samples of HfO2 were grown by either atomic layer deposition (ALD) or pulsed laser deposition (PLD), with the PLD samples having assorted substrate temperatures during deposition (300 C, 500 C, and 750 C). Cathodoluminescence (CL) was chosen as the technique used for studying these HfO2 samples. The CL system used was capable of beam energies ranging from 1 keV to 20 keV and beam currents ranging from 10 μA to 50 μA. A Monte Carlo calculation using CASINO software was performed in order to determine the beam energy for the desired depth of penetration. Measurements were taken at sample temperatures ranging from 7K (closed cycled cryostat) to 300K (room temperature), as well as at various beam energies and beam currents. Comparison will be made between the PLD and ALD spectra.

A Pseudomonas aeruginosa type VI secretion phospholipase D effector targets both prokaryotic and eukaryotic cells.

PubMed

Jiang, Feng; Waterfield, Nicholas R; Yang, Jian; Yang, Guowei; Jin, Qi

2014-05-14

Widely found in animal and plant-associated proteobacteria, type VI secretion systems (T6SSs) are potentially capable of facilitating diverse interactions with eukaryotes and/or other bacteria. Pseudomonas aeruginosa encodes three distinct T6SS haemolysin coregulated protein (Hcp) secretion islands (H1, H2, and H3-T6SS), each involved in different aspects of the bacterium's interaction with other organisms. Here we describe the characterization of a P. aeruginosa H3-T6SS-dependent phospholipase D effector, PldB, and its three tightly linked cognate immunity proteins. PldB targets the periplasm of prokaryotic cells and exerts an antibacterial activity. Surprisingly, PldB also facilitates intracellular invasion of host eukaryotic cells by activation of the PI3K/Akt pathway, revealing it to be a trans-kingdom effector. Our findings imply a potentially widespread T6SS-mediated mechanism, which deploys a single phospholipase effector to influence both prokaryotic cells and eukaryotic hosts. Copyright © 2014 Elsevier Inc. All rights reserved.

An investigation of localised surface plasmon resonance (LSPR) of Ag nanoparticles produced by pulsed laser deposition (PLD) technique

NASA Astrophysics Data System (ADS)

Gezgin, Serap Yiǧit; Kepceoǧlu, Abdullah; Kılıç, Hamdi Şükür

2017-02-01

Noble metal nano-structures such as Ag, Cu, Au are used commonly to increase power conversion efficiency of the solar cell by using their surface plasmons. The plasmonic metal nanoparticles of Ag among others that have strong LSPR in near UV range. They increase photon absorbance via embedding in the active semiconductor of the solar cell. Thin films of Ag are grown in the desired particle size and interparticle distance easily and at low cost by PLD technique. Ag nanoparticle thin films were grown on micro slide glass at 25-36 mJ laser pulse energies under by PLD using ns-Nd:YAG laser. The result of this work have been presented by carrying out UV-VIS and AFM analysis. It was concluded that a laser energy increases, the density and size of Ag-NPs arriving on the substrate increases, and the interparticle distance was decreases. Therefore, LSPR wavelength shifts towards to longer wavelength region.

Salicylic acid induces vanillin synthesis through the phospholipid signaling pathway in Capsicum chinense cell cultures

PubMed Central

Rodas-Junco, Beatriz A; Cab-Guillen, Yahaira; Muñoz-Sanchez, J Armando; Vázquez-Flota, Felipe; Monforte-Gonzalez, Miriam; Hérnandez-Sotomayor, S M Teresa

2013-01-01

Signal transduction via phospholipids is mediated by phospholipases such as phospholipase C (PLC) and D (PLD), which catalyze hydrolysis of plasma membrane structural phospholipids. Phospholipid signaling is also involved in plant responses to phytohormones such as salicylic acid (SA). The relationships between phospholipid signaling, SA, and secondary metabolism are not fully understood. Using a Capsicum chinense cell suspension as a model, we evaluated whether phospholipid signaling modulates SA-induced vanillin production through the activation of phenylalanine ammonia lyase (PAL), a key enzyme in the biosynthetic pathway. Salicylic acid was found to elicit PAL activity and consequently vanillin production, which was diminished or reversed upon exposure to the phosphoinositide-phospholipase C (PI-PLC) signaling inhibitors neomycin and U73122. Exposure to the phosphatidic acid inhibitor 1-butanol altered PLD activity and prevented SA-induced vanillin production. Our results suggest that PLC and PLD-generated secondary messengers may be modulating SA-induced vanillin production through the activation of key biosynthetic pathway enzymes.

Loss of the Mono-ADP-ribosyltransferase, Tiparp, Increases Sensitivity to Dioxin-induced Steatohepatitis and Lethality*

PubMed Central

Ahmed, Shaimaa; Bott, Debbie; Gomez, Alvin; Tamblyn, Laura; Rasheed, Adil; Cho, Tiffany; MacPherson, Laura; Sugamori, Kim S.; Yang, Yang; Grant, Denis M.; Cummins, Carolyn L.; Matthews, Jason

2015-01-01

The aryl hydrocarbon receptor (AHR) mediates the toxic effects of the environmental contaminant dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin; TCDD). Dioxin causes a range of toxic responses, including hepatic damage, steatohepatitis, and a lethal wasting syndrome; however, the mechanisms are still unknown. Here, we show that the loss of TCDD-inducible poly(ADP-ribose) polymerase (Tiparp), an ADP-ribosyltransferase and AHR repressor, increases sensitivity to dioxin-induced toxicity, steatohepatitis, and lethality. Tiparp−/− mice given a single injection of 100 μg/kg dioxin did not survive beyond day 5; all Tiparp+/+ mice survived the 30-day treatment. Dioxin-treated Tiparp−/− mice exhibited increased liver steatosis and hepatotoxicity. Tiparp ADP-ribosylated AHR but not its dimerization partner, the AHR nuclear translocator, and the repressive effects of TIPARP on AHR were reversed by the macrodomain containing mono-ADP-ribosylase MACROD1 but not MACROD2. These results reveal previously unidentified roles for Tiparp, MacroD1, and ADP-ribosylation in AHR-mediated steatohepatitis and lethality in response to dioxin. PMID:25975270

Protective effects of S+ ketamine and atropine against lethality and brain damage during soman-induced status epilepticus in guinea-pigs.

PubMed

Dorandeu, Frederic; Baille, Valerie; Mikler, John; Testylier, Guy; Lallement, Guy; Sawyer, Thomas; Carpentier, Pierre

2007-05-20

Soman poisoning is known to induce full-blown tonic-clonic seizures, status epilepticus (SE), seizure-related brain damage (SRBD) and lethality. Previous studies in guinea-pigs have shown that racemic ketamine (KET), with atropine sulfate (AS), is very effective in preventing death, stopping seizures and protecting sensitive brain areas when given up to 1h after a supra-lethal challenge of soman. The active ketamine isomer, S(+) ketamine (S-KET), is more potent than the racemic mixture and it also induces less side-effects. To confirm the efficacy of KET and to evaluate the potential of S-KET for delayed medical treatment of soman-induced SE, we studied different S-KET dose regimens using the same paradigm used with KET. Guinea-pigs received pyridostigmine (26 microg/kg, IM) 30min before soman (62 microg/kg, 2 LD(50), IM), followed by therapy consisting of atropine methyl nitrate (AMN) (4 mg/kg, IM) 1min following soman exposure. S-KET, with AS (10mg/kg), was then administered IM at different times after the onset of seizures, starting at 1h post-soman exposure. The protective efficacy of S-KET proved to be comparable to KET against lethality and SRBD, but at doses two to three times lower. As with KET, delaying treatment by 2h post-poisoning greatly reduced efficacy. Conditions that may have led to an increased S-KET brain concentration (increased doses or number of injections, adjunct treatment with the oxime HI-6) did not prove to be beneficial. In summary, these observations confirm that ketamine, either racemic or S-KET, in association with AS and possibly other drugs, could be highly effective in the delayed treatment of severe soman intoxication.

Modified pulse laser deposition of Ag nanostructure as intermediate for low temperature Cu-Cu bonding

NASA Astrophysics Data System (ADS)

Liu, Ziyu; Cai, Jian; Wang, Qian; Liu, Lei; Zou, Guisheng

2018-07-01

To lower the Cu-Cu bonding temperature and save the time of the bonding process applied for 3D integration, the Ag nanostructure deposited by pulsed laser deposition (PLD) was designed and decorated on the Cu pads as intermediate. Influences of different PLD process parameters on the designed Ag nanostructure morphology were investigated in this work. The large nanoparticles (NP) defects, NPs coverage rate on the Cu pad, and NPs size distribution were adopted to evaluate the PLD parameters based on the NPs morphology observation and the Cu-Cu bonding quality. The medium laser power of 0.8 W, smaller distance between target and substrate, and protective container should be applied in the optimized PLD to obtain the Ag nanostructure. Then a loose 3D mesh Ag nanostructure consisted of the protrusions and grooves was formed and the morphology observation proved the nanostructure deposition mechanism was contributed to the block of nano-film nucleation and nanoparticles absorption. Finally, the relationship between the bonding temperature and pressure suitable for the Ag nanostructure had been determined based on shear strength and interface observation. The results revealed the combination of higher bonding temperature (250 °C) and lower pressure (20 MPa), or lower bonding temperature (180 °C) and higher pressure (50 MPa) can both achieve the bonding process with the short bonding time of 5 min and annealing at 200 °C for 25 min in vacuum furnace.

Ursodeoxycholic Acid for Treatment of Enlarged Polycystic Liver.

PubMed

Iijima, Takashi; Hoshino, Junichi; Suwabe, Tatsuya; Sumida, Keiichi; Mise, Koki; Kawada, Masahiro; Imafuku, Aya; Hayami, Noriko; Hiramatsu, Rikako; Hasegawa, Eiko; Sawa, Naoki; Takaichi, Kenmei; Ubara, Yoshifumi

2016-02-01

Patients with autosomal dominant polycystic kidney disease and polycystic liver disease (PLD) often have elevated serum levels of alkaline phosphatase (ALP) and gamma-glutamyl transpeptidase (GGT). Ursodeoxycholic acid (UDCA) is used to treat biliary tract diseases, but its effect on PLD remains unclear. UDCA was administered for 1 year at a dose of 300 mg daily to seven PLD patients with elevated ALP or GGT levels who were selected for this treatment by experienced clinicians. Laboratory data and liver volumes were compared among three time points: 1 year before UDCA treatment, at the start of UDCA therapy, and 1 year after the start of therapy. Median GGT did not show a significant change between 1 year before UDCA (180 IU/L) and the start of UDCA therapy (209 IU/L), but it decreased significantly to 98 IU/L after 1 year of UDCA therapy (P = 0.015 vs. the start of therapy). ALP showed a significant increase from 1 year before UDCA (456 IU/L) to the start of UDCA therapy (561 IU/L), and then decreased significantly after 1 year of UDCA therapy (364 IU/L). Median liver volume did not show any significant changes among these three time points of assessment. UDCA may be effective for reducing biliary enzyme levels and inhibiting the growth of liver cysts in patients with PLD. © 2015 International Society for Apheresis, Japanese Society for Apheresis, and Japanese Society for Dialysis Therapy.

Resonant infrared laser deposition of polymer-nanocomposite materials for optoelectronic applications

NASA Astrophysics Data System (ADS)

Park, Hee K.; Schriver, Kenneth E.; Haglund, Richard F.

2011-11-01

Polymers find a number of potentially useful applications in optoelectronic devices. These include both active layers, such as light-emitting polymers and hole-transport layers, and passive layers, such as polymer barrier coatings and light-management films. This paper reports the experimental results for polymer films deposited by resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) and resonant infrared pulsed laser deposition (RIR-PLD) for commercial optoelectronic device applications. In particular, light-management films, such as anti-reflection coatings, require refractive-index engineering of a material. However, refractive indices of polymers fall within a relatively narrow range, leading to major efforts to develop both low- and high-refractive-index polymers. Polymer nanocomposites can expand the range of refractive indices by incorporating low- or high-refractive-index nanoscale materials. RIR-MAPLE is an excellent technique for depositing polymer-nanocomposite films in multilayer structures, which are essential to light-management coatings. In this paper, we report our efforts to engineer the refractive index of a barrier polymer by combining RIR-MAPLE of nanomaterials (for example, high refractive-index TiO2 nanoparticles) and RIR-PLD of host polymer. In addition, we report on the properties of organic and polymer films deposited by RIR-MAPLE and/or RIR-PLD, such as Alq3 [tris(8-hydroxyquinoline) aluminum] and PEDOT:PSS [poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)]. Finally, the challenges and potential for commercializing RIR-MAPLE/PLD, such as industrial scale-up issues, are discussed.

CX-5461 is a DNA G-quadruplex stabilizer with selective lethality in BRCA1/2 deficient tumours

PubMed Central

Xu, Hong; Di Antonio, Marco; McKinney, Steven; Mathew, Veena; Ho, Brandon; O'Neil, Nigel J.; Santos, Nancy Dos; Silvester, Jennifer; Wei, Vivien; Garcia, Jessica; Kabeer, Farhia; Lai, Daniel; Soriano, Priscilla; Banáth, Judit; Chiu, Derek S.; Yap, Damian; Le, Daniel D.; Ye, Frank B.; Zhang, Anni; Thu, Kelsie; Soong, John; Lin, Shu-chuan; Tsai, Angela Hsin Chin; Osako, Tomo; Algara, Teresa; Saunders, Darren N.; Wong, Jason; Xian, Jian; Bally, Marcel B.; Brenton, James D.; Brown, Grant W.; Shah, Sohrab P.; Cescon, David; Mak, Tak W.; Caldas, Carlos; Stirling, Peter C.; Hieter, Phil; Balasubramanian, Shankar; Aparicio, Samuel

2017-01-01

G-quadruplex DNAs form four-stranded helical structures and are proposed to play key roles in different cellular processes. Targeting G-quadruplex DNAs for cancer treatment is a very promising prospect. Here, we show that CX-5461 is a G-quadruplex stabilizer, with specific toxicity against BRCA deficiencies in cancer cells and polyclonal patient-derived xenograft models, including tumours resistant to PARP inhibition. Exposure to CX-5461, and its related drug CX-3543, blocks replication forks and induces ssDNA gaps or breaks. The BRCA and NHEJ pathways are required for the repair of CX-5461 and CX-3543-induced DNA damage and failure to do so leads to lethality. These data strengthen the concept of G4 targeting as a therapeutic approach, specifically for targeting HR and NHEJ deficient cancers and other tumours deficient for DNA damage repair. CX-5461 is now in advanced phase I clinical trial for patients with BRCA1/2 deficient tumours (Canadian trial, NCT02719977, opened May 2016). PMID:28211448

CX-5461 is a DNA G-quadruplex stabilizer with selective lethality in BRCA1/2 deficient tumours.

PubMed

Xu, Hong; Di Antonio, Marco; McKinney, Steven; Mathew, Veena; Ho, Brandon; O'Neil, Nigel J; Santos, Nancy Dos; Silvester, Jennifer; Wei, Vivien; Garcia, Jessica; Kabeer, Farhia; Lai, Daniel; Soriano, Priscilla; Banáth, Judit; Chiu, Derek S; Yap, Damian; Le, Daniel D; Ye, Frank B; Zhang, Anni; Thu, Kelsie; Soong, John; Lin, Shu-Chuan; Tsai, Angela Hsin Chin; Osako, Tomo; Algara, Teresa; Saunders, Darren N; Wong, Jason; Xian, Jian; Bally, Marcel B; Brenton, James D; Brown, Grant W; Shah, Sohrab P; Cescon, David; Mak, Tak W; Caldas, Carlos; Stirling, Peter C; Hieter, Phil; Balasubramanian, Shankar; Aparicio, Samuel

2017-02-17

G-quadruplex DNAs form four-stranded helical structures and are proposed to play key roles in different cellular processes. Targeting G-quadruplex DNAs for cancer treatment is a very promising prospect. Here, we show that CX-5461 is a G-quadruplex stabilizer, with specific toxicity against BRCA deficiencies in cancer cells and polyclonal patient-derived xenograft models, including tumours resistant to PARP inhibition. Exposure to CX-5461, and its related drug CX-3543, blocks replication forks and induces ssDNA gaps or breaks. The BRCA and NHEJ pathways are required for the repair of CX-5461 and CX-3543-induced DNA damage and failure to do so leads to lethality. These data strengthen the concept of G4 targeting as a therapeutic approach, specifically for targeting HR and NHEJ deficient cancers and other tumours deficient for DNA damage repair. CX-5461 is now in advanced phase I clinical trial for patients with BRCA1/2 deficient tumours (Canadian trial, NCT02719977, opened May 2016).

Hypericum perforatum Reduces Paracetamol-Induced Hepatotoxicity and Lethality in Mice by Modulating Inflammation and Oxidative Stress.

PubMed

Hohmann, Miriam S N; Cardoso, Renato D R; Fattori, Victor; Arakawa, Nilton S; Tomaz, José C; Lopes, Norberto P; Casagrande, Rubia; Verri, Waldiceu A

2015-07-01

Hypericum perforatum is a medicinal plant with anti-inflammatory and antioxidant properties, which is commercially available for therapeutic use in Brazil. Herein the effect of H. perforatum extract on paracetamol (acetaminophen)-induced hepatotoxicity, lethality, inflammation, and oxidative stress in male swiss mice were investigated. HPLC analysis demonstrated the presence of rutin, quercetin, hypericin, pseudohypericin, and hyperforin in H. perforatum extract. Paracetamol (0.15-3.0 g/kg, p.o.) induced dose-dependent mortality. The sub-maximal lethal dose of paracetamol (1.5 g/kg, p.o.) was chosen for the experiments in the study. H. perforatum (30-300 mg/kg, i.p.) dose-dependently reduced paracetamol-induced lethality. Paracetamol-induced increase in plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations, and hepatic myeloperoxidase activity, IL-1β, TNF-α, and IFN-γ concentrations as well as decreased reduced glutathione (GSH) concentrations and capacity to reduce 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate radical cation; ABTS˙(+) ) were inhibited by H. perforatum (300 mg/kg, i.p.) treatment. Therefore, H. perforatum protects mice against paracetamol-induced lethality and liver damage. This effect seems to be related to the reduction of paracetamol-induced cytokine production, neutrophil recruitment, and oxidative stress. Copyright © 2015 John Wiley & Sons, Ltd.

An Immature Myeloid/Myeloid-Suppressor Cell Response Associated with Necrotizing Inflammation Mediates Lethal Pulmonary Tularemia

PubMed Central

Periasamy, Sivakumar; Avram, Dorina; McCabe, Amanda; MacNamara, Katherine C.; Sellati, Timothy J.; Harton, Jonathan A.

2016-01-01

Inhalation of Francisella tularensis (Ft) causes acute and fatal pneumonia. The lung cytokine milieu favors exponential Ft replication, but the mechanisms underlying acute pathogenesis and death remain unknown. Evaluation of the sequential and systemic host immune response in pulmonary tularemia reveals that in contrast to overwhelming bacterial burden or cytokine production, an overt innate cellular response to Ft drives tissue pathology and host mortality. Lethal infection with Ft elicits medullary and extra-medullary myelopoiesis supporting recruitment of large numbers of immature myeloid cells and MDSC to the lungs. These cells fail to mature and die, leading to subsequent necrotic lung damage, loss of pulmonary function, and host death that is partially dependent upon immature Ly6G+ cells. Acceleration of this process may account for the rapid lethality seen with Ft SchuS4. In contrast, during sub-lethal infection with Ft LVS the pulmonary cellular response is characterized by a predominance of mature neutrophils and monocytes required for protection, suggesting a required threshold for lethal bacterial infection. Further, eliciting a mature phagocyte response provides transient, but dramatic, innate protection against Ft SchuS4. This study reveals that the nature of the myeloid cell response may be the primary determinant of host mortality versus survival following Francisella infection. PMID:27015566

Loss of cellular transformation efficiency induced by DNA irradiation with low-energy (10 eV) electrons.

PubMed

Kouass Sahbani, Saloua; Sanche, Leon; Cloutier, Pierre; Bass, Andrew D; Hunting, Darel J

2014-11-20

Low energy electrons (LEEs) of energies less than 20 eV are generated in large quantities by ionizing radiation in biological matter. While LEEs are known to induce single (SSBs) and double strand breaks (DSBs) in DNA, their ability to inactivate cells by inducing nonreparable lethal damage has not yet been demonstrated. Here we observe the effect of LEEs on the functionality of DNA, by measuring the efficiency of transforming Escherichia coli with a [pGEM-3Zf (-)] plasmid irradiated with 10 eV electrons. Highly ordered DNA films were prepared on pyrolitic graphite by molecular self-assembly using 1,3-diaminopropane ions (Dap(2+)). The uniformity of these films permits the inactivation of approximately 50% of the plasmids compared to <10% using previous methods, which is sufficient for the subsequent determination of their functionality. Upon LEE irradiation, the fraction of functional plasmids decreased exponentially with increasing electron fluence, while LEE-induced isolated base damage, frank DSB, and non DSB-cluster damage increased linearly with fluence. While DSBs can be toxic, their levels were too low to explain the loss of plasmid functionality observed upon LEE irradiation. Similarly, non-DSB cluster damage, revealed by transforming cluster damage into DSBs by digestion with repair enzymes, also occurred relatively infrequently. The exact nature of the lethal damage remains unknown, but it is probably a form of compact cluster damage in which the lesions are too close to be revealed by purified repair enzymes. In addition, this damage is either not repaired or is misrepaired by E. coli, since it results in plasmid inactivation, when they contain an average of three lesions. Comparison with previous results from a similar experiment performed with γ-irradiated plasmids indicates that the type of clustered DNA lesions, created directly on cellular DNA by LEEs, may be more difficult to repair than those produced by other species from radiolysis.

The Escherichia coli Phospholipase PldA Regulates Outer Membrane Homeostasis via Lipid Signaling.

PubMed

May, Kerrie L; Silhavy, Thomas J

2018-03-20

The outer membrane (OM) bilayer of Gram-negative bacteria is biologically unique in its asymmetrical organization of lipids, with an inner leaflet composed of glycerophospholipids (PLs) and a surface-exposed outer leaflet composed of lipopolysaccharide (LPS). This lipid organization is integral to the OM's barrier properties. Perturbations of the outer leaflet by antimicrobial peptides or defects in LPS biosynthesis or transport to the OM cause a compensatory flipping of PLs to the outer leaflet. As a result, lipid asymmetry is disrupted and OM integrity is compromised. Recently, we identified an Escherichia coli mutant that exhibits aberrant accumulation of surface PLs accompanied by a cellular increase in LPS production. Remarkably, the observed hyperproduction of LPS is PldA dependent. Here we provide evidence that the fatty acids generated by PldA at the OM are transported into the cytoplasm and simultaneously activated by thioesterification to coenzyme A (CoA) by FadD. The acyl-CoAs produced ultimately inhibit LpxC degradation by FtsH. The increased levels of LpxC, the enzyme that catalyzes the first committed step in LPS biosynthesis, increases the amount of LPS produced. Our data suggest that PldA acts as a sensor for lipid asymmetry in the OM. PldA protects the OM barrier by both degrading mislocalized PLs and generating lipid second messengers that enable long-distance signaling that prompts the cell to restore homeostasis at a distant organelle. IMPORTANCE The outer membrane of Gram-negative bacteria is an effective permeability barrier that protects the cell from toxic agents, including antibiotics. Barrier defects are often manifested by phospholipids present in the outer leaflet of this membrane that take up space normally occupied by lipopolysaccharide. We have discovered a signaling mechanism that operates across the entire cell envelope used by the cell to detect these outer membrane defects. A phospholipase, PldA, that functions to degrade these mislocalized phospholipids has a second, equally important function as a sensor. The fatty acids produced by hydrolysis of the phospholipids act as second messengers to signal the cell that more lipopolysaccharide is needed. These fatty acids diffuse across the periplasm and are transported into the cytoplasm by a process that attaches coenzyme A. The acyl-CoA molecule produces signals to inhibit the degradation of the critical enzyme LpxC by the ATP-dependent protease FtsH, increasing lipopolysaccharide production. Copyright © 2018 May and Silhavy.

Ceramide induced mitophagy and tumor suppression

PubMed Central

Dany, Mohammed; Ogretmen, Besim

2015-01-01

Sphingolipids are bioactive lipid effectors, which are involved in the regulation of various cellular signaling pathways. Sphingolipids play essential roles in controlling cell inflammation, proliferation, death, migration, senescence, metastasis and autophagy. Alterations in sphingolipid metabolism has been also implicated in many human cancers. Macroautophagy (referred to here as autophagy) is a form of nonselective sequestering of cytosolic materials by double membrane structures, autophagosomes, which can be either protective or lethal for cells. Ceramide, a central molecule of sphingolipid metabolism is involved in the regulation of autophagy at various levels, including the induction of lethal mitophagy, a selective autophagy process to target and eliminate damaged mitochondria. In this review, we focused on recent studies with regard to the regulation of autophagy, in particular lethal mitophagy, by ceramide, and aimed at providing discussion points for various context-dependent roles and mechanisms of action of ceramide in controlling mitophagy. PMID:25634657

RADIATION-INDUCED GENETIC DAMAGE IN THE MEXICAN TOAD (BUFO VALLICEPS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blair, W.F.

1960-10-01

Lines of Mexican toads (Bufo valliceps) bearing x-ray induced genetic damage were established by mating normal females with males that had received gonadal x-ray doses ranging from 300 to 3000 r. Survival in the first generation was inversely proportional to dose,-as was expected. Toads of the 300-r and l000- r lines were inbred, and toads of these lines and of the 700-r line were outcrossed to normal ones. Two crosses were made between toads of the 500-r and 1000-r lines. Developmental abnormalities of various kinds appeared at life history stages rangthg from early embryonic development to post-metamorphic life in bothmore » inbred and outcross generations. These included abnormal gastrulation and neurulation, larval and post-metamorphic edema, abnormally positioned or missing limbs, optical deficiencies, prognathous jaw due to excessive elongation of the lower jaw, and melanin deficiency. The prognathous jaw, in its extreme expression, would probably be lethal in natural populations because of difficulty of feeding. The melanin deficiency, in its extreme expression, is lethal as metamorphosis fails to occur, and in lesser expression, it appears to be lethal or detrimental. The various abnormalities do not appear to be inherited in any simple way, but instead they vary in expression both within and between generations, possibly in relation to genotype and environment. (auth)« less

Exposure to Sub-lethal 2,4-Dichlorophenoxyacetic Acid Arrests Cell Division and Alters Cell Surface Properties in Escherichia coli.

PubMed

Bhat, Supriya V; Kamencic, Belma; Körnig, André; Shahina, Zinnat; Dahms, Tanya E S

2018-01-01

Escherichia coli is a robust, easily adaptable and culturable bacterium in vitro , and a model bacterium for studying the impact of xenobiotics in the environment. We have used correlative atomic force - laser scanning confocal microscopy (AFM-LSCM) to characterize the mechanisms of cellular response to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). One of the most extensively used herbicides world-wide, 2,4-D is known to cause hazardous effects in diverse non-target organisms. Sub-lethal concentrations of 2,4-D caused DNA damage in E. coli WM1074 during short exposure periods which increased significantly over time. In response to 2,4-D, FtsZ and FtsA relocalized within seconds, coinciding with the complete inhibition of cell septation and cell elongation. Exposure to 2,4-D also resulted in increased activation of the SOS response. Changes to cell division were accompanied by concomitant changes to surface roughness, elasticity and adhesion in a time-dependent manner. This is the first study describing the mechanistic details of 2,4-D at sub-lethal levels in bacteria. Our study suggests that 2,4-D arrests E. coli cell division within seconds after exposure by disrupting the divisome complex, facilitated by dissipation of membrane potential. Over longer exposures, 2,4-D causes filamentation as a result of an SOS response to oxidative stress induced DNA damage.

Cross-Linking Interferes With Assessing Sulfur Mustard-Induced DNA Damage in Human Peripheral Blood Lymphocytes Using the Comet Assay

DTIC Science & Technology

2004-01-01

of SM to impede the migration of H,0 2 -damaged mal ian cell lethality with bifunctional alkylating agents . Chemr. Biol. Iriterui. 38:75-86.DNA is an...3100 Ricketts Point Road, Aberdeen Proving Ground, Maryland 21010-5400 N-3 position of adenine, and alkylation leads to depurination of Sulfur...mustard (SM) is a blistering agent that produces DNA DNA strands. Subsequent breakage of phosphodiester bonds at strand breaks. To detect SM-induced DNA

CLOSE AIR SUPPORT (CAS) FOR COUNTERINSURGENCY (COIN) AND THE UPWARD TRAJECTORY OF UNMANNED AIRCRAFT SYSTEMS (UAS): NAVIGATING THE UNDISCOVERED DOMAIN

DTIC Science & Technology

2015-10-01

collateral damage. Further mitigating collateral damage, “…the SDB Focused Lethality Munition (FLM) variant incorporates a carbon fiber composite ...Effectiveness Modern attack helicopters execute the CAS mission with various standoff weapons. RW assets are slow moving and susceptible to MANPADS and...small arms fire, and attack helicopters used for CAS are primarily in a medium or low threat environment where enemy air defenses are weak or not

DNA Damage Repair and the Emerging Role of Poly(ADP-ribose) Polymerase Inhibition in Cancer Therapeutics.

PubMed

Rabenau, Karen; Hofstatter, Erin

2016-07-01

As a result of improved understanding of DNA repair mechanisms, poly(ADP-ribose) polymerase inhibitors (PARPi) are increasingly recognized to play an important therapeutic role in the treatment of cancer. The aim of this article is to provide a review of PARPi function in DNA damage repair and synthetic lethality and to demonstrate how these mechanisms can be exploited to provide new PARPi-based therapies to patients with solid tumors. Literature from a range of sources, including PubMed and MEDLINE, were searched to identify recent reports regarding DNA damage repair and PARPi. DNA damage repair is central to cellular viability. The family of poly(ADP-ribose) polymerase proteins play multiple intracellular roles in DNA repair, but function primarily in the resolution of repair of single-strand DNA breaks. Insights through the discovery of germline BRCA1/2 mutations led to the understanding of synthetic lethality and the potential therapeutic role of PARPi in the treatment of cancer. Further understanding of DNA damage repair and the concept of BRCA-like tumors have catalyzed PARPi clinical investigation in multiple oncologic settings. PARPi hold great promise in the treatment of solid tumors, both as monotherapy and in combination with other cancer therapeutics. Multiple PARPi clinical trials are currently underway. Further understanding of aberrant DNA repair mechanisms in the germline and in the tumor genome will allow clinicians and researchers to apply PARPi most strategically in the era of personalized medicine. Copyright © 2016 Elsevier HS Journals, Inc. All rights reserved.

Effective vortex pinning in MgB2 thin films

NASA Astrophysics Data System (ADS)

Bugoslavsky, Y.; Cowey, L.; Tate, T. J.; Perkins, G. K.; Moore, J.; Lockman, Z.; Berenov, A.; MacManus-Driscoll, J. L.; Caplin, A. D.; Cohen, L. F.; Zhai, H. Y.; Christen, H. M.; Paranthaman, M. P.; Lowndes, D. H.; Jo, M. H.; Blamire, M. G.

2002-10-01

We discuss the pinning properties of MgB2 thin films grown by pulsed-laser deposition (PLD) and by electron-beam (EB) evaporation. Two mechanisms are identified that contribute most effectively to the pinning of vortices in randomly oriented films. The EB process produces low defected crystallites with a small grain size providing enhanced pinning at grain boundaries without any degradation of Tc. The PLD process produces films with structural disorder on a scale less than the coherence length that further improves pinning, but also depresses Tc.

Association of Corynebacterium pseudotuberculosis recombinant proteins rCP09720 or rCP01850 with rPLD as immunogens in caseous lymphadenitis immunoprophylaxis.

PubMed

Silva, Mara Thais de Oliveira; Bezerra, Francisco Silvestre Brilhante; de Pinho, Rodrigo Barros; Begnini, Karine Rech; Seixas, Fabiana Kommling; Collares, Tiago; Portela, Ricardo Dias; Azevedo, Vasco; Dellagostin, Odir; Borsuk, Sibele

2018-01-02

Caseous lymphadenitis (CLA) is a chronic disease responsible for significant economic losses in sheep and goat breeding worldwide. The treatment for this disease is not effective, and an intense vaccination schedule would be the best control strategy. In this study, we evaluated the associations of rCP09720 or rCP01850 proteins from Corynebacterium pseudotuberculosis with recombinant exotoxin phospholipase D (rPLD) as subunit vaccines in mice. Four experimental groups (10 animals each) were immunized with a sterile 0.9% saline solution (G1), rPLD (G2), rPLD + rCP09720 (G3), and rPLD + rCP01850 (G4). The mice received two doses of each vaccine at a 21-day interval and were challenged 21 days after the last immunization. The animals were evaluated daily for 40 days after the challenge, and mortality rate was recorded. The total IgG production level increased significantly in the experimental groups on day 42 after the first vaccination. Similarly, higher levels of specific IgG2a were observed in experimental groups G2, G3, and G4 compared to the IgG1 levels on day 42. G4 showed a significant (p < .05) humoral response against both antigens of the antigenic formulations. The cellular immune response induced by immunization was characterized by a significant (p < .05) production of interferon-γ compared to that in the control, while the concentrations of interleukin (IL)-4 and IL-12 were not significant in any group. A significant increase of tumor necrosis factor was observed only in G4. The survival rates after the challenge were 30% (rPLD), 40% (rPLD + rCP09720), and 50% (rPLD + rCP01850). Thus, the association of rCP01850 with rPLD resulted in the best protection against the challenge with C. pseudotuberculosis and induced a more intense type 1 T-helper cell immune response. Copyright © 2017 Elsevier Ltd. All rights reserved.

Israel: Background and U.S. Relations

DTIC Science & Technology

2014-07-31

59 End- Use Monitoring...conflict on July 6-7, 2014. Israel began a ground operation in Gaza on July 17 with the stated objective of destroying tunnels used by militants to...means of close-quarters combat (including the use of improvised explosive devices, or IEDs) have proven substantially lethal and damaging. According

The Role of Gap Junction Communication and Oxidative Stress in the Propagation of Toxic Effects among High-Dose α-Particle-Irradiated Human Cells

PubMed Central

Autsavapromporn, Narongchai; de Toledo, Sonia M.; Little, John B.; Jay-Gerin, Jean-Paul; Harris, Andrew L.; Azzam, Edouard I.

2011-01-01

We investigated the roles of gap junction communication and oxidative stress in modulating potentially lethal damage repair in human fibroblast cultures exposed to doses of α particles or γ rays that targeted all cells in the cultures. As expected, α particles were more effective than γ rays at inducing cell killing; further, holding γ-irradiated cells in the confluent state for several hours after irradiation promoted increased survival and decreased chromosomal damage. However, maintaining α-particle-irradiated cells in the confluent state for various times prior to subculture resulted in increased rather than decreased lethality and was associated with persistent DNA damage and increased protein oxidation and lipid peroxidation. Inhibiting gap junction communication with 18-α-glycyrrhetinic acid or by knockdown of connexin43, a constitutive protein of junctional channels in these cells, protected against the toxic effects in α-particle-irradiated cell cultures during confluent holding. Upregulation of antioxidant defense by ectopic overexpression of glutathione peroxidase protected against cell killing by α particles when cells were analyzed shortly after exposure. However, it did not attenuate the decrease in survival during confluent holding. Together, these findings indicate that the damaging effect of α particles results in oxidative stress, and the toxic effects in the hours after irradiation are amplified by intercellular communication, but the communicated molecule(s) is unlikely to be a substrate of glutathione peroxidase. PMID:21388278

Exogenously induced expression of ethylene biosynthesis, ethylene perception, phospholipase D, and Rboh-oxidase genes in broccoli seedlings

PubMed Central

Jakubowicz, Małgorzata; Gałgańska, Hanna; Nowak, Witold; Sadowski, Jan

2010-01-01

In higher plants, copper ions, hydrogen peroxide, and cycloheximide have been recognized as very effective inducers of the transcriptional activity of genes encoding the enzymes of the ethylene biosynthesis pathway. In this report, the transcriptional patterns of genes encoding the 1-aminocyclopropane-1-carboxylate synthases (ACSs), 1-aminocyclopropane-1-carboxylate oxidases (ACOs), ETR1, ETR2, and ERS1 ethylene receptors, phospholipase D (PLD)-α1, -α2, -γ1, and -δ, and respiratory burst oxidase homologue (Rboh)-NADPH oxidase-D and -F in response to these inducers in Brassica oleracea etiolated seedlings are shown. ACS1, ACO1, ETR2, PLD-γ1, and RbohD represent genes whose expression was considerably affected by all of the inducers used. The investigations were performed on the seedlings with (i) ethylene insensitivity and (ii) a reduced level of the PLD-derived phosphatidic acid (PA). The general conclusion is that the expression of ACS1, -3, -4, -5, -7, and -11, ACO1, ETR1, ERS1, and ETR2, PLD-γ 1, and RbohD and F genes is undoubtedly under the reciprocal cross-talk of the ethylene and PAPLD signalling routes; both signals affect it in concerted or opposite ways depending on the gene or the type of stimuli. The results of these studies on broccoli seedlings are in agreement with the hypothesis that PA may directly affect the ethylene signal transduction pathway via an inhibitory effect on CTR1 (constitutive triple response 1) activity. PMID:20581125

Phospholipase D and the Maintenance of Phosphatidic Acid Levels for Regulation of Mammalian Target of Rapamycin (mTOR)*

PubMed Central

Foster, David A.; Salloum, Darin; Menon, Deepak; Frias, Maria A.

2014-01-01

Phosphatidic acid (PA) is a critical metabolite at the heart of membrane phospholipid biosynthesis. However, PA also serves as a critical lipid second messenger that regulates several proteins implicated in the control of cell cycle progression and cell growth. Three major metabolic pathways generate PA: phospholipase D (PLD), diacylglycerol kinase (DGK), and lysophosphatidic acid acyltransferase (LPAAT). The LPAAT pathway is integral to de novo membrane phospholipid biosynthesis, whereas the PLD and DGK pathways are activated in response to growth factors and stress. The PLD pathway is also responsive to nutrients. A key target for the lipid second messenger function of PA is mTOR, the mammalian/mechanistic target of rapamycin, which integrates both nutrient and growth factor signals to control cell growth and proliferation. Although PLD has been widely implicated in the generation of PA needed for mTOR activation, it is becoming clear that PA generated via the LPAAT and DGK pathways is also involved in the regulation of mTOR. In this minireview, we highlight the coordinated maintenance of intracellular PA levels that regulate mTOR signals stimulated by growth factors and nutrients, including amino acids, lipids, glucose, and Gln. Emerging evidence indicates compensatory increases in one source of PA when another source is compromised, highlighting the importance of being able to adapt to stressful conditions that interfere with PA production. The regulation of PA levels has important implications for cancer cells that depend on PA and mTOR activity for survival. PMID:24990952

Phospholipase D and the maintenance of phosphatidic acid levels for regulation of mammalian target of rapamycin (mTOR).

PubMed

Foster, David A; Salloum, Darin; Menon, Deepak; Frias, Maria A

2014-08-15

Phosphatidic acid (PA) is a critical metabolite at the heart of membrane phospholipid biosynthesis. However, PA also serves as a critical lipid second messenger that regulates several proteins implicated in the control of cell cycle progression and cell growth. Three major metabolic pathways generate PA: phospholipase D (PLD), diacylglycerol kinase (DGK), and lysophosphatidic acid acyltransferase (LPAAT). The LPAAT pathway is integral to de novo membrane phospholipid biosynthesis, whereas the PLD and DGK pathways are activated in response to growth factors and stress. The PLD pathway is also responsive to nutrients. A key target for the lipid second messenger function of PA is mTOR, the mammalian/mechanistic target of rapamycin, which integrates both nutrient and growth factor signals to control cell growth and proliferation. Although PLD has been widely implicated in the generation of PA needed for mTOR activation, it is becoming clear that PA generated via the LPAAT and DGK pathways is also involved in the regulation of mTOR. In this minireview, we highlight the coordinated maintenance of intracellular PA levels that regulate mTOR signals stimulated by growth factors and nutrients, including amino acids, lipids, glucose, and Gln. Emerging evidence indicates compensatory increases in one source of PA when another source is compromised, highlighting the importance of being able to adapt to stressful conditions that interfere with PA production. The regulation of PA levels has important implications for cancer cells that depend on PA and mTOR activity for survival. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Characteristics of the surface layer of barium strontium titanate thin films deposited by laser ablation

NASA Astrophysics Data System (ADS)

Craciun, V.; Singh, R. K.

2000-04-01

Ba0.5Sr0.5TiO3 (BST) thin films grown on Si by an in situ ultraviolet-assisted pulsed laser deposition (UVPLD) technique exhibited significantly higher dielectric constant and refractive index values and lower leakage current densities than films grown by conventional PLD under similar conditions. X-ray photoelectron spectroscopy (XPS) investigations have shown that the surface layer of the grown films contained, besides the usual BST perovskite phase, an additional phase with Ba atoms in a different chemical state. PLD grown films always exhibited larger amounts of this phase, which was homogeneously mixed with the BST phase up to several nm depth, while UVPLD grown films exhibited a much thinner (˜1 nm) and continuous layer. The relative fraction of this phase was not correlated with the amount of C atoms present on the surface. Fourier transform infrared spectroscopy did not find any BaCO3 contamination layer, which was believed to be related to this new phase. X-ray diffraction measurement showed that although PLD grown films contained less oxygen atoms, the lattice parameter was closer to the bulk value than that of UVPLD grown films. After 4 keV Ar ion sputtering for 6 min, XPS analysis revealed a small suboxide Ba peak for the PLD grown films. This finding indicates that the average Ba-O bonds are weaker in these films, likely due to the presence of oxygen vacancies. It is suggested here that this new Ba phase corresponds to a relaxed BST surface layer.

Carbon monoxide-induced suspended animation protects against hypoxic damage in Caenorhabditis elegans

PubMed Central

Nystul, Todd G.; Roth, Mark B.

2004-01-01

Oxygen deprivation is a major cause of cellular damage and death. Here we demonstrate that Caenorhabditis elegans embryos, which can survive both in anoxia (<0.001 kPa O2) by entering into suspended animation and in mild hypoxia (0.25-1 kPa O2) through a hypoxia-inducible factor 1-mediated response, cannot survive in intermediate concentrations of oxygen, between 0.01 and 0.1 kPa O2. Moreover, we show that carbon monoxide can protect C. elegans embryos against hypoxic damage in this sensitive range. Carbon monoxide can also rescue the hypoxia-sensitive mutant hif-1(ia04) from lethality in hypoxia. This work defines the oxygen tensions over which hypoxic damage occurs in C. elegans embryos and demonstrates that carbon monoxide can prevent this damage by inducing suspended animation. PMID:15184665

Why is intracellular ice lethal? A microscopical study showing evidence of programmed cell death in cryo-exposed embryonic axes of recalcitrant seeds of Acer saccharinum

PubMed Central

Wesley-Smith, James; Walters, Christina; Pammenter, N. W.

2015-01-01

Background and Aims Conservation of the genetic diversity afforded by recalcitrant seeds is achieved by cryopreservation, in which excised embryonic axes (or, where possible, embryos) are treated and stored at temperatures lower than −180 °C using liquid nitrogen. It has previously been shown that intracellular ice forms in rapidly cooled embryonic axes of Acer saccharinum (silver maple) but this is not necessarily lethal when ice crystals are small. This study seeks to understand the nature and extent of damage from intracellular ice, and the course of recovery and regrowth in surviving tissues. Methods Embryonic axes of A. saccharinum, not subjected to dehydration or cryoprotection treatments (water content was 1·9 g H2O g−1 dry mass), were cooled to liquid nitrogen temperatures using two methods: plunging into nitrogen slush to achieve a cooling rate of 97 °C s−1 or programmed cooling at 3·3 °C s−1. Samples were thawed rapidly (177 °C s−1) and cell structure was examined microscopically immediately, and at intervals up to 72 h in vitro. Survival was assessed after 4 weeks in vitro. Axes were processed conventionally for optical microscopy and ultrastructural examination. Key Results Immediately following thaw after cryogenic exposure, cells from axes did not show signs of damage at an ultrastructural level. Signs that cells had been damaged were apparent after several hours of in vitro culture and appeared as autophagic decomposition. In surviving tissues, dead cells were sloughed off and pockets of living cells were the origin of regrowth. In roots, regrowth occurred from the ground meristem and procambium, not the distal meristem, which became lethally damaged. Regrowth of shoots occurred from isolated pockets of surviving cells of peripheral and pith meristems. The size of these pockets may determine the possibility for, the extent of and the vigour of regrowth. Conclusions Autophagic degradation and ultimately autolysis of cells following cryo-exposure and formation of small (0·2–0·4 µm) intracellular ice crystals challenges current ideas that ice causes immediate physical damage to cells. Instead, freezing stress may induce a signal for programmed cell death (PCD). Cells that form more ice crystals during cooling have faster PCD responses. PMID:25808653

Characterization of PLD grown WO3 thin films for gas sensing

NASA Astrophysics Data System (ADS)

Boyadjiev, Stefan I.; Georgieva, Velichka; Stefan, Nicolaie; Stan, George E.; Mihailescu, Natalia; Visan, Anita; Mihailescu, Ion N.; Besleaga, Cristina; Szilágyi, Imre M.

2017-09-01

Tungsten trioxide (WO3) thin films were grown by pulsed laser deposition (PLD) with the aim to be applied in gas sensors. The films were studied by atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and profilometry. To study the gas sensing behavior of these WO3 films, they were deposited on quartz resonators and the quartz crystal microbalance (QCM) method was applied to analyze their gas sensitivity. Synthesis of tetragonal-WO3 films starting from a target with predominantly monoclinic WO3 phase was observed. The films deposited at 300 °C presented a surface topology favorable for the sorption properties, consisting of a film matrix with protruding craters/cavities. QCM prototype sensors with such films were tested for NO2 sensing. The PLD grown WO3 thin films show good sensitivity and fast reaction at room temperature, even in as-deposited state. With the presented technology, the manufacturing of QCM gas sensors is simple, fast and cost-effective, and it is also suitable for energy-effective portable equipment for on-line monitoring of environmental changes.

Acylethanolamides and endocannabinoid signaling system in dorsal striatum of rats exposed to perinatal asphyxia.

PubMed

Holubiec, Mariana I; Romero, Juan I; Blanco, Eduardo; Tornatore, Tamara Logica; Suarez, Juan; Rodríguez de Fonseca, Fernando; Galeano, Pablo; Capani, Francisco

2017-07-13

Endocannabinoids (eCBs) and acylethanolamides (AEs) have lately received more attention due to their neuroprotective functions in neurological disorders. Here we analyze the alterations induced by perinatal asphyxia (PA) in the main metabolic enzymes and receptors of the eCBs/AEs in the dorsal striatum of rats. To induce PA, we used a model developed by Bjelke et al. (1991). Immunohistochemical techniques were carried out to determine the expression of neuronal and glial markers (NeuN and GFAP), eCBs/AEs synthesis and degradation enzymes (DAGLα, NAPE-PLD and FAAH) and their receptors (CB1 and PPARα). We found a decrease in NAPE-PLD and PPARα expression. Since NAPE-PLD and PPARα take part in the production and reception of biochemical actions of AEs, such as oleoylethanolamide, these results may suggest that PA plays a key role in the regulation of this system. These data agree with previous results obtained in the hippocampus and encourage us to develop further studies using AEs as potential neuroprotective compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

Growth mechanism of superconducting MgB2 films prepared by various methods

NASA Astrophysics Data System (ADS)

Zhai, H. Y.; Christen, H. M.; Zhang, L.; Paranthaman, M.; Cantoni, C.; Sales, B. C.; Fleming, P. H.; Christen, D. K.; Lowndes, D. H.

2001-10-01

The growth mechanisms of MgB2 films obtained by different methods on various substrates are compared via a detailed cross-sectional scanning electron microscopy (SEM) study. The analyzed films include (a) samples obtained by an ex-situ post-anneal at 900 degree of e-beam evaporated boron in the presence of an Mg vapor (exhibiting bulk-like Tc0 about 38.8 K), (b) samples obtained by the same ex-situ 900 degree anneal of pulsed laser deposition (PLD)-grown Mg+B precursors (exhibiting Tc0 ~ 25 K), and (c) films obtained by a low-temperature (600 - 630 degree) in-situ anneal of PLD-grown Mg+B precursors (with Tc0 about 24 K). A significant oxygen contamination was also present in films obtained from a PLD-grown precursors. On the other hand, it is clearly observed that the films obtained by the high-temperature reaction of e-beam evaporated B with Mg vapor are formed by the nucleation of independent MgB2 grains at the film surface, indicating that this approach may not be suitable to obtain smooth and (possibly) epitaxial films.

Rapid mitogenic regulation of the mTORC1 inhibitor, DEPTOR, by phosphatidic acid.

PubMed

Yoon, Mee-Sup; Rosenberger, Christina L; Wu, Cong; Truong, Nga; Sweedler, Jonathan V; Chen, Jie

2015-05-07

The mammalian target of rapamycin complex 1 (mTORC1) is regulated, in part, by the endogenous inhibitor DEPTOR. However, the mechanism of DEPTOR regulation with regard to rapid mTORC1 activation remains unknown. We report that DEPTOR is rapidly and temporarily dissociated from mTORC1 upon mitogenic stimulation, suggesting a mechanism underlying acute mTORC1 activation. This mitogen-stimulated DEPTOR dissociation is blocked by inhibition or depletion of the mTORC1 regulator, phospholipase D (PLD), and recapitulated with the addition of the PLD product phosphatidic acid (PA). Our mass spectrometry analysis has independently identified DEPTOR as an mTOR binding partner dissociated by PA. Interestingly, only PA species with unsaturated fatty acid chains, such as those produced by PLD, are capable of displacing DEPTOR and activating mTORC1, with high affinity for the FRB domain of mTOR. Our findings reveal a mechanism of mTOR regulation and provide a molecular explanation for the exquisite specificity of PA function. Copyright © 2015 Elsevier Inc. All rights reserved.

Targeting hearing health messages for users of personal listening devices.

PubMed

Punch, Jerry L; Elfenbein, Jill L; James, Richard R

2011-06-01

To summarize the literature on patterns and risks of personal listening device (PLD) use, which is ubiquitous among teenagers and young adults. The review emphasizes risk awareness, health concerns of PLD users, inclination to take actions to prevent hearing loss from exposure to loud music, and specific instructional messages that are likely to motivate such preventive actions. We conducted a systematic, critical review of the English-language scholarly literature on the topic of PLDs and their potential effects on human hearing. We used popular database search engines to locate relevant professional journals, books, recent conference papers, and other reference sources. Adolescents and young adults appear to have somewhat different perspectives on risks to hearing posed by PLD use. Messages designed to suggest actions they might take in avoiding or reducing these risks, therefore, need to be targeted to achieve optimal outcomes. We offer specific recommendations regarding the framing and content of educational messages that are most likely to be effective in reducing the potentially harmful effects of loud music on hearing in these populations, and we note future research needs.

Temperature studies of optical parameters of (Ag3AsS3)0.6(As2S3)0.4 thin films prepared by rapid thermal evaporation and pulse laser deposition

NASA Astrophysics Data System (ADS)

Studenyak, I. P.; Kutsyk, M. M.; Buchuk, M. Yu.; Rati, Y. Y.; Neimet, Yu. Yu.; Izai, V. Yu.; Kökényesi, S.; Nemec, P.

2016-02-01

(Ag3AsS3)0.6(As2S3)0.4 thin films were deposited using rapid thermal evaporation (RTE) and pulse laser deposition (PLD) techniques. Ag-enriched micrometre-sized cones (RTE) and bubbles (PLD) were observed on the thin film surface. Optical transmission spectra of the thin films were studied in the temperature range 77-300 K. The Urbach behaviour of the optical absorption edge in the thin films due to strong electron-phonon interaction was observed, the main parameters of the Urbach absorption edge were determined. Temperature dependences of the energy position of the exponential absorption edge and the Urbach energy are well described in the Einstein model. Dispersion and temperature dependences of refractive indices were analysed; a non-linear increase of the refractive indices with temperature was revealed. Disordering processes in the thin films were studied and compared with bulk composites, the differences between the thin films prepared by RTE and PLD were analysed.

Gamma rays induce DNA damage and oxidative stress associated with impaired growth and reproduction in the copepod Tigriopus japonicus.

PubMed

Han, Jeonghoon; Won, Eun-Ji; Lee, Bo-Young; Hwang, Un-Ki; Kim, Il-Chan; Yim, Joung Han; Leung, Kenneth Mei Yee; Lee, Yong Sung; Lee, Jae-Seong

2014-07-01

Nuclear radioisotope accidents are potentially ecologically devastating due to their impact on marine organisms. To examine the effects of exposure of a marine organism to radioisotopes, we irradiated the intertidal copepod Tigriopus japonicus with several doses of gamma radiation and analyzed the effects on mortality, fecundity, and molting by assessing antioxidant enzyme activities and gene expression patterns. No mortality was observed at 96h, even in response to exposure to a high dose (800Gy) of radiation, but mortality rate was significantly increased 120h (5 days) after exposure to 600 or 800Gy gamma ray radiation. We observed a dose-dependent reduction in fecundity of ovigerous females; even the group irradiated with 50Gy showed a significant reduction in fecundity, suggesting that gamma rays are likely to have a population level effect. In addition, we observed growth retardation, particularly at the nauplius stage, in individuals after gamma irradiation. In fact, nauplii irradiated with more than 200Gy, though able to molt to copepodite stage 1, did not develop into adults. Upon gamma radiation, T. japonicus showed a dose-dependent increase in reactive oxygen species (ROS) levels, the activities of several antioxidant enzymes, and expression of double-stranded DNA break damage genes (e.g. DNA-PK, Ku70, Ku80). At a low level (sub-lethal dose) of gamma irradiation, we found dose-dependent upregulation of p53, implying cellular damage in T. japonicus in response to sub-lethal doses of gamma irradiation, suggesting that T. japonicus is not susceptible to sub-lethal doses of gamma irradiation. Additionally, antioxidant genes, phase II enzyme (e.g. GSTs), and cellular chaperone genes (e.g. Hsps) that are involved in cellular defense mechanisms also showed the same expression patterns for sublethal doses of gamma irradiation (50-200Gy). These findings indicate that sublethal doses of gamma radiation can induce oxidative stress-mediated DNA damage and increase the expression of antioxidant enzymes and proteins with chaperone-related functions, thereby significantly affecting life history parameters such as fecundity and molting in the copepod T. japonicus. Copyright © 2014 Elsevier B.V. All rights reserved.

Electromagnetic pulse (EMP) coupling codes for use with the vulnerability/lethality (VIL) taxonomy. Final report, June-October 1984

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mar, M.H.

1995-07-01

Based on the vulnerability Lethality (V/L) taxonomy developed by the Ballistic Vulnerability Lethality Division (BVLD) of the Survivability Lethality Analysis Directorate (SLAD), a nuclear electromagnetic pulse (EMP) coupling V/L analysis taxonomy has been developed. A nuclear EMP threat to a military system can be divided into two levels: (1) coupling to a system level through a cable, antenna, or aperture; and (2) the component level. This report will focus on the initial condition, which includes threat definition and target description, as well as the mapping process from the initial condition to damaged components state. EMP coupling analysis at a systemmore » level is used to accomplish this. This report introduces the nature of EMP threat, interaction between the threat and target, and how the output of EMP coupling analysis at a system level becomes the input to the component level analysis. Many different tools (EMP coupling codes) will be discussed for the mapping process, which correponds to the physics of phenomenology. This EMP coupling V/L taxonomy and the models identified in this report will provide the tools necessary to conduct basic V/L analysis of EMP coupling.« less

PLD growth of CoPd thin films and characterization of their magnetic properties by magneto optical Kerr effect

NASA Astrophysics Data System (ADS)

Sedrpooshan, Mehran; Ahmadvand, Hossein; Ranjbar, Mehdi; Salamati, Hadi

2018-06-01

CoPd alloy thin films with different thicknesses and Co/Pd ratios have been deposited on Si (100) substrate by pulsed laser deposition (PLD). The magnetic properties were investigated by using the magneto-optical Kerr effect (MOKE) in both longitudinal and polar geometries. The results show that the films with thickness in the range of 6-24 nm, deposited at a low substrate temperature of 200 °C, are mostly magnetized in the plane of film. Higher deposition temperature forces the magnetic easy axis to orient in the perpendicular direction of the films.

Inter-annual and spatial difference in hatch date and settlement date distribution and planktonic larval duration in yellow striped flounder Pseudopleuronectes herzensteini

NASA Astrophysics Data System (ADS)

Joh, Mikimasa; Wada, Akihiko

2018-07-01

Hatch date and settlement date distribution and planktonic larval duration (PLD) in yellow striped flounder in nursery grounds in the northern Japan Sea and in the Okhotsk Sea around Hokkaido (Northern Japan Sea-Okhotsk Sea population) were investigated. We examined the relationship between the ecological features and water temperature in these two locations where oceanographic conditions considerably differ. For both nursery grounds, the timing of hatch was early in a warm year and late in a cold year, indicating the strong link between water temperature and the timing of hatch in this population. Although spatial difference in hatch date in 2007 was not significant, hatching and settlement of juveniles collected in the Okhotsk Sea nursery (Okhotsk Sea subpopulation: OSS) occurred later than in those collected in the Japan Sea (Japan Sea subpopulation: JSS); in the spring, the water temperature of the Japan Sea rises earlier in the southern area. The precise area where eggs of both subpopulations originated is unknown; however, this study indicates that eggs that become the JSS may be produced further south than those for the OSS. Comparing on the same date, the water temperature around potential spawning area of OSS in 2006 was ca. 2 °C lower than in 2007 and 2009; however, the overall difference in water temperature at the median date of hatching was 0.7 °C. This result indicates that a spring rise in water temperature probably determines the timing of spawning and larval hatch of this population. Spatiotemporal differences in the PLD were affected by water temperature in which juveniles were exposed during pelagic phase. The PLDs were shorter in warmer years and for warmer subpopulation. The PLD of OSS was longer than that of JSS and spatial difference was statistically significant in 2006. Water temperature in which OSS was exposed in later pelagic phase was relatively low, and the growth of pelagic larvae of OSS was probably slow, and consequently, the PLD of OSS may become long. The eggs originating the OSS are spawned in the Japan Sea and transported a long-distance to their nursery ground in Okhotsk Sea. Generally, a slow growth rate is considered a negative factor for the early survival of fish, although it may be that the slow growth and long PLD of the OSS juveniles confers an advantage upon them during their long-distance transportation. For yellow striped flounder, this study primarily reports on hatch date and settlement date distribution and PLD of juveniles. For flatfish species, the study of the link between those features and water temperature is limited. This study expands the knowledge of the early life-cycle in flatfish, information on which is currently limited.

Normal and grazing incidence pulsed laser deposition of nanostructured MoSx hydrogen evolution catalysts from a MoS2 target

NASA Astrophysics Data System (ADS)

Fominski, V. Yu.; Romanov, R. I.; Fominski, D. V.; Dzhumaev, P. S.; Troyan, I. A.

2018-06-01

Pulsed laser ablation of a MoS2 target causes enhanced splashing of the material. So, for MoSx films obtained by pulsed laser deposition (PLD) in the conventional normal incidence (NI) configuration, their typical morphology is characterized by an underlying granular structure with an overlayer of widely dispersed spherical Mo and MoSx particles possessing micro-, sub-micro- and nanometer sizes. We investigated the possibility of using high surface roughness, which occurs due to particle deposition, as a support with a large exposed surface area for thin MoSx catalytic layers for the hydrogen evolution reaction (HER). For comparison, the HER performance of MoSx layers formed by grazing incidence (GI) PLD was studied. During GI-PLD, a substrate was placed along the direction of laser plume transport and few large particles loaded the substrate. The local structure and composition of thin MoSx layers formed by the deposition of the vapor component of the laser plume were varied by changing the pressure of the buffer gas (argon, Ar). In the case of NI-PLD, an increase in Ar pressure caused the formation of quasi-amorphous MoSx (x ≥ 2) films that possessed highly active catalytic sites on the edges of the layered MoS2 nanophase. At the same time, a decrease in the deposition rate of the MoSx film appeared due to the scattering of the vapor flux by Ar molecules during flux transport from the target to the substrate. This effect prevented uniform deposition of the MoSx catalytic film on the surface of most particles, whose deposition rate was independent of Ar pressure. The scattered vapor flux containing Mo and S atoms was a dominant source for MoSx film growth during GI-PLD. The thickness and composition distribution of the MoSx film on the substrate depended on both the pressure of the buffer gas and the distance from the target. For 1.0-2.5 cm from the target, the deposition rate was quite sufficient to form S-enriched quasi-amorphous MoSx (2.5 < x < 6) catalytic films that consisted of densely packed 30-50 nm nanoparticles. The GI-PLD films possessed a greater density of catalytically active sites with a distinct local atomic configuration including edge sites of the layered MoS2 nanophase and diverse S ligands in the amorphous phase, which contained Mo3-S clusters. At a modest loading of ∼300 μg/cm2 on glassy carbon substrates and an overpotential of -140 mV, these films activated H2 production with geometric current densities up to -10 mA/cm2.

Interleukin 4 receptor signaling in human monocytes and U937 cells involves the activation of a phosphatidylcholine-specific phospholipase C: a comparison with chemotactic peptide, FMLP, phospholipase D, and sphingomyelinase

PubMed Central

1994-01-01

Interleukin 4 (IL-4) diminishes cytokine activation of human macrophage. IL-4 binding to monocyte IL-4R is associated with protein kinase C (PKC) translocation to a nuclear fraction. The cleavage of diacyglycerol (DAG), an activator of PKC, from membrane phospholipids was investigated to define the proximal events of IL-4R signaling. IL-4 induced a statistically significant time-and dose-dependent generation of DAG. The IL-4-triggered production of DAG was not derived from phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis, since neither cytosolic calcium flux nor liberation of inositol phosphates was detected in response to IL-4. Experiments were performed using [14C- methyl]choline-labeled U937 cells and monocytes to determine whether IL- 4R activated phospholipase C (PLC), PLD, or PLA2 to use membrane phosphatidylcholine (PC) to form DAG. IL-4 induced a time- and dose- dependent increase of phosphocholine (pchol) with concomitant degradation of membrane PC (p < 0.05 compared with control). The finding that the peak reduction of PC was equivalent to peak production of pchol suggested that IL-4R signaling involved the activation of a PC- specific PLC. Changes in choline (chol) or lyso-PC and glycerolphosphocholine, the respective products of PC cleavage by PLD or PLA2, were not detected in IL-4-treated cells. In contrast, exogenous PLD induced an increase in chol and concomitant loss of membrane PC. Additional investigation suggested that IL-4R signaling does not involve PLD. In cells labeled with L-lyso-3-PC 1-[1- 14C]palmitoyl, PLD but not IL-4, increased the production of phosphatidic acid (PA) and phosphatidyl-ethanol when pretreated with ethanol. Propranolol, an inhibitor of phosphatidate phosphohydrolase, and calyculin A, a phosphatase 1 and 2A inhibitor, blocked DAG production in response to FMLP but not to IL-4. In propranolol pretreated cells, PMA but not IL-4 triggered the production of PA and lowered the amount of DAG. Evidence that PLA2 is not coupled to IL-4R is the detection of arachidonate production in response to FMLP but not to IL-4. Furthermore, IL-4R is not coupled to sphingomyelinase (SMase) since IL-4, unlike exogenous SMase, did not generate ceramide but induced the hydrolysis of PC to pchol that was comparable to exogenous PLC. In summary, IL-4R signaling in monocytes and U937 cells involves PLC and not PLD, PLA2, or SMase, and it uses PC and not PIP2 to form DAG. PMID:7931078

Occurrence and mobility of mercury in groundwater: Chapter 5

USGS Publications Warehouse

Barringer, Julia L.; Szabo, Zoltan; Reilly, Pamela A.; Bradley, Paul M.

2013-01-01

Mercury (Hg) has long been identified as an element that is injurious, even lethal, to living organisms. Exposure to its inorganic form, mainly from elemental Hg (Hg(0)) vapor (Fitzgerald & Lamborg, 2007) can cause damage to respiratory, neural, and renal systems (Hutton, 1987; USEPA, 2012; WHO, 2012). The organic form, methylmercury (CH3Hg+; MeHg), is substantially more toxic than the inorganic form (Fitzgerald & Lamborg, 2007). Methylmercury attacks the nervous system and exposure can prove lethal, as demonstrated by well-known incidents such as those in 1956 in Minimata, Japan (Harada, 1995), and 1971 in rural Iraq (Bakir et al., 1973), where, in the former, industrial release of MeHg into coastal waters severely tainted the fish caught and eaten by the local population, and in the latter, grain seed treated with an organic mercurial fungicide was not planted, but eaten in bread instead. Resultant deaths are not known with certainty but have been estimated at about 100 and 500, respectively (Hutton, 1987). Absent such lethal accidents, human exposure to MeHg comes mainly from ingestion of piscivorous fish in which MeHg has accumulated, with potential fetal damage ascribed to high fish diets during their mothers’ pregnancies (USEPA, 2001). Lesser human exposure occurs through ingestion of drinking water (USEPA, 2001), where concentrations of total Hg (THg; inorganic plus organic forms) typically are in the low nanograms-per-liter range[1] - , particularly from many groundwater sources, and concentrations at the microgram-per-liter level are rare.

Wolf management in the 21st century: From public input to sterilization

USGS Publications Warehouse

Mech, L.D.; Fritts, S.H.; Nelson, M.E.

1996-01-01

Human-population increase and land development portend increasing conflict with large predators. Concurrently, changes and diversification of human attitudes are bringing increased disagreement about wildlife management. Animal-rights advocacy resulting from urbanization of human populations conflicts with traditional wildlife management. These forces focus more on wolves than on other wildlife because of strong public and media interest in wolves. Thus wolf management in the future will come under even greater public scrutiny, involve more public input, and may have greater restrictions imposed on it. This will lead to increased complexity in wolf management including more zoning, more experimentation with lethal and non-lethal capture techniques and alternate methods of alleviating damage to pets, livestock, and large ungulate herds, and greater public and private subsidy of wolf damage. One form of non-lethal control of wolf populations that may hold some promise is direct sterilization of males to reduce the biotic potential of the wolf population. Experimental vasectomy of five wild male wolves from four packs in Minnesota indicates that sterile males will continue to hold mates and territories, which would be necessary if sterilization is to be a viable technique for assisting with population control. If sterile males held territories but failed to produce pups, such territories might contain only about a third the number of wolves as fertile pack territories. Because wolves are long-lived in unexploited populations and their territories are large, direct sterilization of relatively few animals each year might significantly reduce populations.

Exposure to Sub-lethal 2,4-Dichlorophenoxyacetic Acid Arrests Cell Division and Alters Cell Surface Properties in Escherichia coli

PubMed Central

Bhat, Supriya V.; Kamencic, Belma; Körnig, André; Shahina, Zinnat; Dahms, Tanya E. S.

2018-01-01

Escherichia coli is a robust, easily adaptable and culturable bacterium in vitro, and a model bacterium for studying the impact of xenobiotics in the environment. We have used correlative atomic force – laser scanning confocal microscopy (AFM-LSCM) to characterize the mechanisms of cellular response to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). One of the most extensively used herbicides world-wide, 2,4-D is known to cause hazardous effects in diverse non-target organisms. Sub-lethal concentrations of 2,4-D caused DNA damage in E. coli WM1074 during short exposure periods which increased significantly over time. In response to 2,4-D, FtsZ and FtsA relocalized within seconds, coinciding with the complete inhibition of cell septation and cell elongation. Exposure to 2,4-D also resulted in increased activation of the SOS response. Changes to cell division were accompanied by concomitant changes to surface roughness, elasticity and adhesion in a time-dependent manner. This is the first study describing the mechanistic details of 2,4-D at sub-lethal levels in bacteria. Our study suggests that 2,4-D arrests E. coli cell division within seconds after exposure by disrupting the divisome complex, facilitated by dissipation of membrane potential. Over longer exposures, 2,4-D causes filamentation as a result of an SOS response to oxidative stress induced DNA damage. PMID:29472899

The cytotoxic mechanism of karlotoxin 2 (KmTx 2) from Karlodinium veneficum (Dinophyceae)

PubMed Central

Deeds, Jonathan R.; Hoesch, Robert E.; Place, Allen R.; Kao, Joseph P.Y.

2015-01-01

This study demonstrates that the polyketide toxin karlotoxin 2 (KmTx 2) produced by Karlodinium veneficum, a dinoflagellate associated with fish kills in temperate estuaries worldwide, alters vertebrate cell membrane permeability. Microfluorimetric and electrophysiological measurements were used to determine that vertebrate cellular toxicity occurs through non-selective permeabilization of plasma membranes, leading to osmotic cell lysis. Previous studies showed that KmTx 2 is lethal to fish at naturally-occurring concentrations measured during fish kills, while sub-lethal doses severely damage gill epithelia. This study provides a mechanistic explanation for the association between K. veneficum blooms and fish kills that has long been observed in temperate estuaries worldwide. PMID:25546005

The lethal interaction of x ray and penicillin induced lesions following x-irradiation of Escherichia coli B/r in the presence of hypoxic cell sensitizers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gillies, N.E.; Obioha, F.I.

When Escherichia coli B/r were x-irradiated under anoxia in the presence of different electron-affinic sensitizers and then incubated in broth containing penicillin (at a concentration that did not kill unirradiated cells) additional killing of the bacteria occurred provided the sensitizers were of relatively high lipophilicity. The overall effect was to increase the efficiency of these sensitizers. It is concluded that sensitizer-dependent latent radiation lesions(s) are produced in membrane components of the cell envelope that interact with damage caused by penicillin in the peptidoglycan layer and this causes the additional lethality.

EXPRESSION OF INDUCIBLE HSP70 ENHANCES THE PROLIFERATION OF MCF-7 BREAST CANCER CELLS AND PROTECTS AGAINST THE CYTOTOXIC EFFECTS OF HYPERTHERMIA

EPA Science Inventory

Heat shock proteins (HSPs) are ubiquitous proteins that are induced following exposure to sub-lethal heat shock, are highly conserved during evolution and protect cells from damage through their function as molecular chaperones. Some cancers demonstrate elevated levels of Hsp70 ...

ASSESSING THE INFLUENCE OF PLANT GROWTH REGULATOR HERBICIDE VAPOR DRIFT ON ARTHROPOD COMMUNITIES IN FIELD CROP AGRO-ECOSYSTEMS

EPA Science Inventory

Sub-lethal herbicide damage is likely to have negative consequences for plant health. This in turn could lead to positive or negative effects on insects. Plants that are not healthy may not provide the best floral resources for pollinators, potentially further stressing hon...

Hemolysis-induced lethality involves inflammasome activation by heme

PubMed Central

Dutra, Fabianno F.; Alves, Letícia S.; Rodrigues, Danielle; Fernandez, Patricia L.; de Oliveira, Rosane B.; Golenbock, Douglas T.; Zamboni, Dario S.; Bozza, Marcelo T.

2014-01-01

The increase of extracellular heme is a hallmark of hemolysis or extensive cell damage. Heme has prooxidant, cytotoxic, and inflammatory effects, playing a central role in the pathogenesis of malaria, sepsis, and sickle cell disease. However, the mechanisms by which heme is sensed by innate immune cells contributing to these diseases are not fully characterized. We found that heme, but not porphyrins without iron, activated LPS-primed macrophages promoting the processing of IL-1β dependent on nucleotide-binding domain and leucine rich repeat containing family, pyrin domain containing 3 (NLRP3). The activation of NLRP3 by heme required spleen tyrosine kinase, NADPH oxidase-2, mitochondrial reactive oxygen species, and K+ efflux, whereas it was independent of heme internalization, lysosomal damage, ATP release, the purinergic receptor P2X7, and cell death. Importantly, our results indicated the participation of macrophages, NLRP3 inflammasome components, and IL-1R in the lethality caused by sterile hemolysis. Thus, understanding the molecular pathways affected by heme in innate immune cells might prove useful to identify new therapeutic targets for diseases that have heme release. PMID:25225402

Hemolysis-induced lethality involves inflammasome activation by heme.

PubMed

Dutra, Fabianno F; Alves, Letícia S; Rodrigues, Danielle; Fernandez, Patricia L; de Oliveira, Rosane B; Golenbock, Douglas T; Zamboni, Dario S; Bozza, Marcelo T

2014-09-30

The increase of extracellular heme is a hallmark of hemolysis or extensive cell damage. Heme has prooxidant, cytotoxic, and inflammatory effects, playing a central role in the pathogenesis of malaria, sepsis, and sickle cell disease. However, the mechanisms by which heme is sensed by innate immune cells contributing to these diseases are not fully characterized. We found that heme, but not porphyrins without iron, activated LPS-primed macrophages promoting the processing of IL-1β dependent on nucleotide-binding domain and leucine rich repeat containing family, pyrin domain containing 3 (NLRP3). The activation of NLRP3 by heme required spleen tyrosine kinase, NADPH oxidase-2, mitochondrial reactive oxygen species, and K(+) efflux, whereas it was independent of heme internalization, lysosomal damage, ATP release, the purinergic receptor P2X7, and cell death. Importantly, our results indicated the participation of macrophages, NLRP3 inflammasome components, and IL-1R in the lethality caused by sterile hemolysis. Thus, understanding the molecular pathways affected by heme in innate immune cells might prove useful to identify new therapeutic targets for diseases that have heme release.

Substantial changes in hemocyte parameters of Manila clam Ruditapes philippinarum two years after the Hebei Spirit oil spill off the west coast of Korea.

PubMed

Hong, Hyun-Ki; Donaghy, Ludovic; Kang, Chang-Keun; Kang, Hyun-Sil; Lee, Hee-Jung; Park, Heung-Sik; Choi, Kwang-Sik

2016-07-15

Two years after the Hebei Spirit oil spill occurred off the west coast of Korea, we determined sub-lethal effects of the spilled oil on hemocyte parameters of Ruditapes philippinarum in the damaged areas. Clams in the spilled sites displayed unusually high proportion of granulocytes, which may result in higher phagocytosis capacity and reactive oxygen species production. Hemocytes in clams from the polluted sites also displayed less DNA damage and mortality than in the control site, possibly due to a faster phagocytosis of the impaired cells. Glycogen, the major energetic reserve, was depleted in clams from the spilled sites, potentially due to energetic consumption for maintenance of a large pool of granulocytes, detoxification processes and oxidative stress. Modified hemocyte parameters in clams in the spilled area, may reflect sub-lethal physiological stresses caused by the residual oils in the sediment, in conjunction with environmental modifications such as food availability and pathogens pattern. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Dynamic model of seasonal breeding rodent pest population controlled with short-acting sterilant].

PubMed

Liu, Han-wu; Jin, Zhen; Zhang, Feng-qin; Li, Qiu-ying

2013-04-01

Rodent pests bring great damage to human beings, while rodenticide and sterilant can be used to control the pests. After ingesting sterilant, rodent pests lose their fertility, but in some cases, the sterile individuals may gain their fertility again, produce offspring, and enlarge population size. In this paper, the dynamic models of rodent pest population under lethal control and shortacting contraception control were formulated, and, with the prerequisite of the seasonal breeding of rodent pest population, the models were used to regularly analyze their behaviors and the effects of the contraception rate, lethal rate, control interval, and sterilant valid period on the dynamics of the pest population. The results showed that larger contraception rate and lethal rate and shorter control interval could have better control effect, making the controlled population become smaller and even died out. Short-acting sterilant limited the control effect. At the later period of breeding season, the rodent pest population controlled with short-acting sterilant would have a weak recovery.

[Damage control in trauma patients with hemodynamic instability].

PubMed

Müller, Thorben; Doll, Dietrich; Kliebe, Frank; Ruchholtz, Steffen; Kühne, Christian

2010-10-01

The term "Damage-control" is borrowed from naval terminology. It means the initial control of a damaged ship. Because of the lethal triad in multiple injured patients the classical concept of definitive surgically therapy in the acute phase of the injury has a high rate of complications such as exsanguination, sepsis, heart failure and multiple organ failure. The core idea of the damage control concept was to minimize the additional trauma by surgical operations in these critical patients in the first phase. This means temporary control of a hemorrhage and measures for stopping abdominal contamination. After 24 - 48 hours in the intensive care unit and correction of physiological disturbances further interventions are performed for definitively treatment of the injuries. Summarized, the damage control strategy comprises an abbreviated operation, intensive care unit resuscitation, and a return to the operating room for the definitive operation after hemodynamic stabilisation of the patient. © Georg Thieme Verlag Stuttgart · New York.

Influence of Corynebacterium pseudotuberculosis infection on level of acute phase proteins in goats.

PubMed

Jeber, Z K H; MohdJin, Z; Jesse, F F; Saharee, A A; Sabri, J; Yusoff, R; Wahid, H

2016-03-09

Goat caseous lymphadenitis (CLA) is a chronic disease caused by Corynebacterium pseudotuberculosis. However, there is paucity of data about goat's acute phase response during the course of CLA. This study was conducted to investigate the response of acute phase proteins, mainly haptoglobin (Hp), serum amyloid A (SAA) and the negative acute phase response, especially albumin after an experimental challenge of C. pseudotuberculosis and phospholipase D (PLD) in Cross bred Boer goats. Serum Hp concentration in goats challenged with C. pseudotuberculosis (inoculated with 1x10(9) cfu subcutaneously) showed a significant increase, 5 fold in males (0.98 ± 0.12 mg/ml) and 3 fold in females (0.66 ± 0.12 mg/ml) compared to the control (0.2 ± 0.02 mg/ml). Challenge with PLD (1 ml/20 kg body weight intravenously) also showed significant increase, 4 fold in males and females (0.89 ± 0.11 mg/ml; 0.82 ± 0.12 mg/ml) respectively compared to the control (0.2 ± 0.02 mg/ml). Albumin concentration showed a significant decrease in both treated groups compared to the control. There were no significant changes in SAA concentration between challenged and control goats. There was a significant response by Hp to C. pseudotuberculosis infection and PLD challenge. This was supported by the early acute response in which Hp was detected before CLA lesions were developed. Therefore, it concluded that C. pseudotuberculosis and PLD can influence the level of acute phase proteins in goats.

Development of Long REBCO with BMO Coated Conductors by PLD Method with High Production Rate

NASA Astrophysics Data System (ADS)

Ibi, A.; Yoshida, T.; Taneda, T.; Yoshizumi, M.; Izumi, T.; Shiohara, Y.

We have been developing long REBa2Cu3O7-δ (RE: Y, Gd and Eu etc.) with BaMO3 (M: Zr, Sn and Hf etc.) coated conductors by the combination of the ion-beam assisted deposition (IBAD) and the pulsed laser deposition (PLD) methods. REBa2Cu3O7-δ with BaMO3 coated conductors showed high in-field performance, therefore, these coated conductors could be expected for the industrial and commercial applications at high temperatures in magnetic fields. However, to realize the low production cost for long REBa2Cu3O7-δ with BaMO3 coated conductors, improvement of the production rate of the REBa2Cu3O7-δ layers containing BaMO3 rods with maintaining high superconducting properties is required. To solve these problems, we have tried deposition of the REBa2Cu3O7-δ layers with high superconducting properties by the PLD method with high production rate. As a result, we have successfully fabricated EuBa2Cu3O7-δ layers containing BaHfO3 rods with high in-field Jc and Ic by the PLD method with high production rate. This EuBa2Cu3O7-δ with BaHfO3 coated conductor exhibit a high Ic value of 412 and 48.7 A/cm-width at 77 K in self-field and 3 T, respectively at the deposition rate of about 40 μm/h and the production rate of 10 m/h for a 1.35 μm EuBCO layer thick.

Activation of Src and release of intracellular calcium by phosphatidic acid during Xenopus laevis fertilization

PubMed Central

Bates, Ryan C.; Fees, Colby P.; Holland, William L.; Winger, Courtney C.; Batbayar, Khulan; Ancar, Rachel; Bergren, Todd; Petcoff, Douglas; Stith, Bradley J.

2014-01-01

We report a new step in the fertilization in Xenopus laevis which has been found to involve activation of Src tyrosine kinase to stimulate phospholipase C-γ (PLC- γ) which increases inositol 1,4,5-trisphosphate (IP3) to release intracellular calcium ([Ca]i). Molecular species analysis and mass measurements suggested that sperm activate phospholipase D (PLD) to elevate phosphatidic acid (PA). We now report that PA mass increased 2.7 fold by 1 minute after insemination and inhibition of PA production by two methods inhibited activation of Src and PLCγ, increased [Ca]i and other fertilization events. As compared to 14 other lipids, PA strongly bound Xenopus Src but not PLCγ. Addition of synthetic PA activated egg Src (an action requiring intact lipid rafts) and PLCγ as well as doubling the amount of PLCγ in rafts. In the absence of elevated [Ca]i, PA addition elevated IP3 mass to levels equivalent to that induced by sperm (but twice that achieved by calcium ionophore). Finally, PA induced [Ca]i release that was blocked by an IP3 receptor inhibitor. As only PLD1b message was detected, and Western blotting did not detect PLD2, we suggest that sperm activate PLD1b to elevate PA which then binds to and activates Src leading to PLCγ stimulation, IP3 elevation and [Ca]i release. Due to these and other studies, PA may also play a role in membrane fusion events such as sperm-egg fusion, cortical granule exocytosis, the elevation of phosphatidylinositol 4,5-bisphosphate and the large, late increase in sn 1,2-diacylglycerol in fertilization. PMID:24269904

Phospholipase cleavage of D- and L-chiro-glycosylphosphoinositides asymmetrically incorporated into liposomal membranes.

PubMed

Bonilla, Julia B; Cid, M Belén; Contreras, F-Xabier; Goñi, Félix M; Martín-Lomas, Manuel

2006-02-01

The nature of chiro-inositol-containing inositolphosphoglycans (IPGs), reported to be putative insulin mediators, was studied by examination of the substrate specificities of the phosphatidylinositol-specific phospholipase C (PI-PLC) and the glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD) by using a series of synthetic D- and L-chiro-glycosylphosphoinositides. 3-O-alpha-D-Glucosaminyl- (3) and -galactosaminyl-2-phosphatidyl-L-chiro-inositol (4), which show the maximum stereochemical similarity to the 6-O-alpha-D-glucosaminylphosphatidylinositol pseudodisaccharide motifs of GPI anchors, were synthesized and asymmetrically incorporated into phospholipid bilayers in the form of large unilamellar vesicles (LUVs). Similarly, 2-O-alpha-D-glucosaminyl- (5) and -galactosaminyl-1-phosphatidyl-D-chiro-inositol (6), which differ from the corresponding pseudodisaccharide motif of the GPI anchors only in the axial orientation of the phosphatidyl moiety, were also synthesized and asymmetrically inserted into LUVs. The cleavage of these synthetic molecules in the liposomal constructs by PI-PLC from Bacillus cereus and by GPI-PLD from bovine serum was studied with the use of 6-O-alpha-D-glucosaminylphosphatidylinositol (7) and the conserved GPI anchor structure (8) as positive controls. Although PI-PLC cleaved 3 and 4 with about the same efficiency as 7 and 8, this enzyme did not accept 5 or 6. GPI-PLD accepted both the L-chiro- (3 and 4) and the D-chiro- (5 and 6) glycosylinositolphosphoinositides. Therefore, IPGs containing L-chiro-inositol only are expected to be released from chiro-inositol-containing GPIs if the cleavage is effected by a PI-PLC, whereas GPI-PLD cleavage could result in both L-chiro- and D-chiro-inositol-containing IPGs.

Activation of Src and release of intracellular calcium by phosphatidic acid during Xenopus laevis fertilization.

PubMed

Bates, Ryan C; Fees, Colby P; Holland, William L; Winger, Courtney C; Batbayar, Khulan; Ancar, Rachel; Bergren, Todd; Petcoff, Douglas; Stith, Bradley J

2014-02-01

We report a new step in the fertilization in Xenopus laevis which has been found to involve activation of Src tyrosine kinase to stimulate phospholipase C-γ (PLC-γ) which increases inositol 1,4,5-trisphosphate (IP3) to release intracellular calcium ([Ca](i)). Molecular species analysis and mass measurements suggested that sperm activate phospholipase D (PLD) to elevate phosphatidic acid (PA). We now report that PA mass increased 2.7 fold by 1 min after insemination and inhibition of PA production by two methods inhibited activation of Src and PLCγ, increased [Ca](i) and other fertilization events. As compared to 14 other lipids, PA specifically bound Xenopus Src but not PLCγ. Addition of synthetic PA activated egg Src (an action requiring intact lipid rafts) and PLCγ as well as doubling the amount of PLCγ in rafts. In the absence of elevated [Ca](i), PA addition elevated IP3 mass to levels equivalent to that induced by sperm (but twice that achieved by calcium ionophore). Finally, PA induced [Ca](i) release that was blocked by an IP3 receptor inhibitor. As only PLD1b message was detected, and Western blotting did not detect PLD2, we suggest that sperm activate PLD1b to elevate PA which then binds to and activates Src leading to PLCγ stimulation, IP3 elevation and [Ca](i) release. Due to these and other studies, PA may also play a role in membrane fusion events such as sperm-egg fusion, cortical granule exocytosis, the elevation of phosphatidylinositol 4,5-bisphosphate and the large, late increase in sn 1,2-diacylglycerol in fertilization. © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Differences in phosphatidic acid signalling and metabolism between ABA and GA treatments of barley aleurone cells.

PubMed

Villasuso, Ana Laura; Di Palma, Maria A; Aveldaño, Marta; Pasquaré, Susana J; Racagni, Graciela; Giusto, Norma M; Machado, Estela E

2013-04-01

Phosphatidic acid (PA) is the common lipid product in abscisic acid (ABA) and gibberellic acid (GA) response. In this work we investigated the lipid metabolism in response to both hormones. We could detect an in vivo phospholipase D activity (PLD, EC 3.1.4.4). This PLD produced [(32)P]PA (phosphatidic acid) rapidly (minutes) in the presence of ABA, confirming PA involvement in signal transduction, and transiently, indicating rapid PA removal after generation. The presence of PA removal by phosphatidate phosphatase 1 and 2 isoforms (E.C. 3.1.3.4) was verified in isolated aleurone membranes in vitro, the former but not the latter being specifically responsive to the presence of GA or ABA. The in vitro DGPP phosphatase activity was not modified by short time incubation with GA or ABA while the in vitro PA kinase - that allows the production of 18:2-DGPP from 18:2-PA - is stimulated by ABA. The long term effects (24 h) of ABA or GA on lipid and fatty acid composition of aleurone layer cells were then investigated. An increase in PC and, to a lesser extent, in PE levels is the consequence of both hormone treatments. ABA, in aleurone layer cells, specifically activates a PLD whose product, PA, could be the substrate of PAP1 and/or PAK activities. Neither PLD nor PAK activation can be monitored by GA treatment. The increase in PAP1 activity monitored after ABA or GA treatment might participate in the increase in PC level observed after 24 h hormone incubation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

The Chloroplast-Localized Phospholipases D α4 and α5 Regulate Herbivore-Induced Direct and Indirect Defenses in Rice1[C][W

PubMed Central

Qi, Jinfeng; Zhou, Guoxin; Yang, Lijuan; Erb, Matthias; Lu, Yanhua; Sun, Xiaoling; Cheng, Jiaan; Lou, Yonggen

2011-01-01

The oxylipin pathway is of central importance for plant defensive responses. Yet, the first step of the pathway, the liberation of linolenic acid following induction, is poorly understood. Phospholipases D (PLDs) have been hypothesized to mediate this process, but data from Arabidopsis (Arabidopsis thaliana) regarding the role of PLDs in plant resistance have remained controversial. Here, we cloned two chloroplast-localized PLD genes from rice (Oryza sativa), OsPLDα4 and OsPLDα5, both of which were up-regulated in response to feeding by the rice striped stem borer (SSB) Chilo suppressalis, mechanical wounding, and treatment with jasmonic acid (JA). Antisense expression of OsPLDα4 and -α5 (as-pld), which resulted in a 50% reduction of the expression of the two genes, reduced elicited levels of linolenic acid, JA, green leaf volatiles, and ethylene and attenuated the SSB-induced expression of a mitogen-activated protein kinase (OsMPK3), a lipoxygenase (OsHI-LOX), a hydroperoxide lyase (OsHPL3), as well as a 1-aminocyclopropane-1-carboxylic acid synthase (OsACS2). The impaired oxylipin and ethylene signaling in as-pld plants decreased the levels of herbivore-induced trypsin protease inhibitors and volatiles, improved the performance of SSB and the rice brown planthopper Nilaparvata lugens, and reduced the attractiveness of plants to a larval parasitoid of SSB, Apanteles chilonis. The production of trypsin protease inhibitors in as-pld plants could be partially restored by JA, while the resistance to rice brown planthopper and SSB was restored by green leaf volatile application. Our results show that phospholipases function as important components of herbivore-induced direct and indirect defenses in rice. PMID:21984727

Vinculin in subsarcolemmal densities in chicken skeletal muscle: localization and relationship to intracellular and extracellular structures.

PubMed

Shear, C R; Bloch, R J

1985-07-01

Using immunocytochemical methods we have studied the distribution of vinculin in the anterior and posterior latissimus dorsi skeletal (ALD and PLD, respectively) muscles of the adult chicken. The ALD muscle is made up of both tonic (85%) and twitch (15%) myofibers, and the PLD muscle is made up entirely of twitch myofibers. In indirect immunofluorescence, antivinculin antibodies stained specific regions adjacent to the sarcolemma of the ALD and PLD muscles. In the central and myotendinous regions of the ALD, staining of the tonic fibers was intense all around the fiber periphery. Staining of the twitch fibers of both ALD and PLD muscles was intense only at neuromuscular junctions and myotendinous regions. Electron microscopy revealed subsarcolemmal, electron-dense plaques associated with the membrane only in those regions where vinculin was localized by immunofluorescence. Using antivinculin antibody and protein A conjugated to colloidal gold, we found that the electron-dense subsarcolemmal densities in the tonic fibers of the ALD contain vinculin; no other structures were labeled. The basal lamina overlying the densities appeared to be connected to the sarcolemma by fine, filamentous structures, more enriched at these sites than elsewhere along the muscle fiber. Increased amounts of endomysial connective tissue were often found just outside the basal lamina near the densities. In tonic ALD muscle fibers, the subsarcolemmal densities were present preferentially over the I-bands. In partially contracted ALD muscle, subsarcolemmal densities adjacent to the Z-disk appeared to be connected to that structure by short filaments. We propose that in the ALD muscle, through their association with the extracellular matrix, the densities stabilize the muscle membrane and perhaps assist in force transmission.

Investigation of thick PLD-GdBCO and ZrO2 doped GdBCO coated conductors with high critical current on PLD-CeO2 capped IBAD-GZO substrate tapes

NASA Astrophysics Data System (ADS)

Takahashi, K.; Kobayashi, H.; Yamada, Y.; Ibi, A.; Fukushima, H.; Konishi, M.; Miyata, S.; Shiohara, Y.; Kato, T.; Hirayama, T.

2006-09-01

In order to increase the critical current, Ic, we have fabricated thick GdBa2Cu3O7-δ (GdBCO) coated conductors (CCs) by the pulsed laser deposition (PLD) method on PLD-CeO2/ion-beam assisted deposition (IBAD)-Gd2Zr2O7 (GZO)/hastelloy metal substrate tapes. The highest critical current value was 522 A cm-1 for a thickness of 3.6 µm in self-field at 77 K. It was found that a low volume fraction of a-axis orientated grains was obtained in the thick GdBCO CCs, compared to YBa2Cu3O7-δ (YBCO) CCs. Consequently, the GdBCO CCs showed higher critical current density (Jc) than YBCO CCs in all thicknesses from 0.2 to 3.6 µm. Furthermore, we have succeeded in improving Ic in a magnetic field by the introduction of artificial pinning centres using a 5 mol% ZrO2 doped GdBCO target. In the measurement of the Ic dependence on the magnetic field angle, θ, Ic was much improved, especially at 0°, i.e., with the magnetic field parallel to the c-axis. The Ic value at 3 T was 59.5 A cm-1 at 0° and it showed a minimum of 42.3 A cm-1 at 82° for 2.28 µm thick CC. The minimum value in the angular dependence of Ic at 3 T was about five times higher than that of YBCO CC and two times higher than that of pure GdBCO CC.

The chloroplast-localized phospholipases D α4 and α5 regulate herbivore-induced direct and indirect defenses in rice.

PubMed

Qi, Jinfeng; Zhou, Guoxin; Yang, Lijuan; Erb, Matthias; Lu, Yanhua; Sun, Xiaoling; Cheng, Jiaan; Lou, Yonggen

2011-12-01

The oxylipin pathway is of central importance for plant defensive responses. Yet, the first step of the pathway, the liberation of linolenic acid following induction, is poorly understood. Phospholipases D (PLDs) have been hypothesized to mediate this process, but data from Arabidopsis (Arabidopsis thaliana) regarding the role of PLDs in plant resistance have remained controversial. Here, we cloned two chloroplast-localized PLD genes from rice (Oryza sativa), OsPLDα4 and OsPLDα5, both of which were up-regulated in response to feeding by the rice striped stem borer (SSB) Chilo suppressalis, mechanical wounding, and treatment with jasmonic acid (JA). Antisense expression of OsPLDα4 and -α5 (as-pld), which resulted in a 50% reduction of the expression of the two genes, reduced elicited levels of linolenic acid, JA, green leaf volatiles, and ethylene and attenuated the SSB-induced expression of a mitogen-activated protein kinase (OsMPK3), a lipoxygenase (OsHI-LOX), a hydroperoxide lyase (OsHPL3), as well as a 1-aminocyclopropane-1-carboxylic acid synthase (OsACS2). The impaired oxylipin and ethylene signaling in as-pld plants decreased the levels of herbivore-induced trypsin protease inhibitors and volatiles, improved the performance of SSB and the rice brown planthopper Nilaparvata lugens, and reduced the attractiveness of plants to a larval parasitoid of SSB, Apanteles chilonis. The production of trypsin protease inhibitors in as-pld plants could be partially restored by JA, while the resistance to rice brown planthopper and SSB was restored by green leaf volatile application. Our results show that phospholipases function as important components of herbivore-induced direct and indirect defenses in rice.

HOST-PARASITE FACTORS IN GROUP A STREPTOCOCCAL INFECTIONS

PubMed Central

Watson, Dennis W.

1960-01-01

The factors present in streptococcal lesion extracts (SLE) which enhanced the lethal and tissue-damaging properties of Gram-negative bacterial endotoxins and streptolysin O were identified with the scarlet fever group of toxins. Toxic manifestations attributed to this group of toxins included lethality, cardiotoxic and other tissue damage, enhancement of toxicity, and pyrogenicity. Of these, the measurement of febrile response in American Dutch rabbits was the most useful parameter of toxicity. In rabbits, repeated daily intravenous injections of 0.125 Lf of a purified erythrogenic toxin immunizes specifically against the pyrogenic activity; this technique was used to type the toxins and to distinguish them from exogenous and endogenous pyrogens; non-specific pyrogens, such as streptococcal endotoxin, were not found in SLE. All types of the Lancefield Group A streptococci tested produced one or or more immunologically distinct toxins in vivo in contrast to Groups B and C which did not produce them; toxins A and B, previously distinguished by neutralization of rash-inducing activity in the skin, were produced in vivo. The A toxin was the most common, as indicated by its presence in extracts prepared with Types 28, 12, 17, and 10 (NY-5); B toxin was found in 10 (NY-5) and 19. A new toxin, designated C, was obtained from a Type 18. In American Dutch rabbits, purified toxin at a concentration of 15 Lf (900,000 STD) neither gave a Dick test nor prepared the skin for the local Shwartzman reaction; by this route, however, in contrast to classical endotoxins, they enhance the lethal and tissue-damaging properties of sublethal doses of these and other toxins. These properties of the immunologic distinct exotoxins as demonstrated in American Dutch rabbits suggest by analogy their importance in the pathogenesis of streptococcal disease in man. Evidence that might implicate them in sequelae, in addition to scarlet fever, is discussed. PMID:13783427

Lysosome and Phagosome Stability in Lethal Cell Injury

PubMed Central

Hawkins, Hal K.; Ericsson, Jan L. E.; Biberfeld, Peter; Trump, Benjamin F.

1972-01-01

In two types of cell injury in a tissue culture system, the possibility was tested that lysosome rupture may be a lethal cellular reaction to injury, and thus an important general cause of irreversibility of damage in injured tissue. Prior labeling of secondary lysosomes with the fluorochrome acridine orange, or with ferritin, was used to trace changes in lysosomes after applying an injury. The metabolic inhibitors iodoacetate and cyanide were used together to block the cell's energy supply, or attachment of antiserum and subsequent complement attack were used to damage the surface membrane, producing rapid loss of cell volume control. Living cells were studied by time-lapse phase-contrast cinemicrography and fluorescence microscopy, and samples were fixed at intervals for electron microscopy. The cytolytic action of complement was lethal to sensitized cells within 2 hours, but results showed that lysosomes did not rupture for approximately 4 hours and in fact did not release the fluorescent dye until after reaching the postmortem necrotic phase of injury. Cells treated with metabolic inhibitors also showed irreversible alterations, while lysosomes remained intact and retained the ferritin marker. The fluorochrome marker, acridine orange, escaped from lysosomes early after metabolic injury, but the significance of this observation is not clear. The results are interpreted as evidence against the concept that lysosome rupture threatens the survival of injured cells. The original suicide bag mechanism of cell damage thus is apparently not operative in the systems studied. Lysosomes appear to be relatively stable organelles which, following injury of the types studied, burst only after cell death, acting then as scavengers which help to clear cellular debris. ImagesFigs 5-7Fig 18Fig 19Fig 20Figs 21-23Fig 8Fig 9Fig 10Fig 11Figs 24-27Fig 12Figs 13 and 14Fig 1Fig 2Fig 3Fig 4Fig 15Fig 16Fig 17 PMID:4340333

Biochemical and genotoxic response of naphthalene to fingerlings of milkfish Chanos chanos.

PubMed

Palanikumar, L; Kumaraguru, A K; Ramakritinan, C M

2013-09-01

The present study investigated the acute toxicity, sub-lethal toxicity and biochemical response of naphthalene in fingerlings of milkfish Chanos chanos. The 96 h acute toxicity LC50 values for C. chanos exposed to naphthalene was 5.18 μg l(-1). The estimated no observed effect concentration and lowest observed effect concentration values for naphthalene in C. chanos were 0.42 and 0.69 μg l(-1) respectively for 30 days. The estimated maximum allowable toxicant concentration for naphthalene was 0.53 μg l(-1). Biochemical enzyme markers such as lipid peroxidation, catalase, glutathione S transferase and reduced glutathione were measured in gills and liver tissues of C. chanos exposed to sub-lethal concentrations of naphthalene. Fluctuation in lipid peroxidation and catalase level suggests that naphthalene concentrations play a vital role in induction of oxidative stress in fish. Induction of reduced glutathione level and inhibition of glutathione S-transferase level was observed in naphthalene exposed C. chanos suggesting that there may be enhanced oxidative damage due to free radicals. Increasing concentration increases in number of nuclear abnormalities. The formation of micronuclei and binucleated micronuclei induction by naphthalene confirm its genotoxic potential. The highest levels of DNA damage (% tail length) were observed at 1.24 μg l(-1) of naphthalene. The study suggests that biochemical enzymes, nuclear abnormalities and DNA damage index can serve as a biological marker for naphthalene contamination.

Spectroscopic study of Pbs nano-structured layer prepared by Pld utilized as a Hall-effect magnetic sensor

NASA Astrophysics Data System (ADS)

Atwa, D. M.; Aboulfotoh, N.; El-magd, A. Abo; Badr, Y.

2013-10-01

Lead sulfide (PbS) nano-structured films have been grown on quartz substrates using PLD technique. The deposited films were characterized by several structural techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Selected-area electron diffraction patterns (SAED). The results prove the formation of cubic phase of PbS nanocrystals. Elemental analysis of the deposited films compared to the bulk target was obtained via laser induced fluorescence of the produced plasma particles and the energy dispersive X-ray "EDX" technique. The Hall coefficient measurements indicate an efficient performance of the deposited films as a magnetic sensor.

Phosphatidic acid induces decidualization by stimulating Akt-PP2A binding in human endometrial stromal cells.

PubMed

Lee, So Young; Lee, Yun Young; Choi, Joong Sub; Yoon, Mee-Sup; Han, Joong-Soo

2016-11-01

Decidualization of human endometrial stromal cells (hESCs) is crucial for successful uterine implantation and maintaining pregnancy. We previously reported that phospholipase D1 (PLD1) is required for cAMP-induced decidualization of hESCs. However, the mechanism by which phosphatidic acid (PA), the product of PLD1 action, might regulate decidualization is not known. We confirmed that PA induced decidualization of hESCs by observing morphological changes and measuring increased levels of decidualization markers such as IGFBP1 and prolactin transcripts (P < 0.05). Treatment with PA reduced phosphorylation of Akt and consequently that of FoxO1, which led to the increased IGFBP1 and prolactin mRNA levels (P < 0.05). Conversely, PLD1 knockdown rescued Akt phosphorylation. Binding of PP2A and Akt increased in response to cAMP or PA, suggesting that their binding is directly responsible for the inactivation of Akt during decidualization. Consistent with this observation, treatment with okadaic acid, a PP2A inhibitor, also inhibited cAMP-induced decidualization by blocking Akt dephosphorylation. © 2016 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

Arabidopsis phospholipase D alpha 1-derived phosphatidic acid regulates microtubule organization and cell development under microtubule-interacting drugs treatment.

PubMed

Zhang, Qun; Qu, Yana; Wang, Qing; Song, Ping; Wang, Peipei; Jia, Qianru; Guo, Jinhe

2017-01-01

Phospholipase D (PLD) and its product phosphatidic acid (PA) are emerging as essential regulators of cytoskeleton organization in plants. However, the underlying molecular mechanisms of PA-mediated microtubule reorganization in plants remain largely unknown. In this study, we used pharmacological and genetic approaches to analyze the function of Arabidopsis thaliana PLDα1 in the regulation of microtubule organization and cell development in response to microtubule-affecting drugs. Treatment with the microtubule-stabilizing drug paclitaxel resulted in less growth inhibition and decreased rightward slant of roots, longitudinal alignment of microtubules, and enhanced length of hypocotyl epidermal cells in the pldα1 mutant, the phenotype of which was rescued by exogenous application of PA. Moreover, the pldα1 mutant was sensitive to the microtubule-disrupting drugs oryzalin and propyzamide in terms of seedling survival ratio, left-skewing angle of roots and microtubule organization. In addition, both disruption and stabilization of microtubules induced by drugs activated PLDα1 activity. Our findings demonstrate that in A. thaliana, PLDα1/PA might regulate cell development by modulating microtubule organization in an activity-dependent manner.

Growth of Cu2ZnSnS4(CZTS) by Pulsed Laser Deposition for Thin film Photovoltaic Absorber Material

NASA Astrophysics Data System (ADS)

Nandur, Abhishek; White, Bruce

2014-03-01

CZTS (Cu2ZnSnS4) has become the subject of intense interest because it is an ideal candidate absorber material for thin-film solar cells with an optimal band gap (1.5 eV), high absorption coefficient (104 cm-1) and abundant elemental components. Pulsed Laser Deposition (PLD) provides excellent control over film composition since thin films are deposited under high vacuum with excellent stoichiometry transfer from the target. CZTS thin films were deposited using PLD from a stoichiometrically close CZTS target (Cu2.6Zn1.1Sn0.7S3.44). The effects of laser energy fluence and substrate temperature and post-deposition sulfur annealing on the surface morphology, composition and optical absorption have been investigated. Optimal CZTS thin films exhibited a band gap of 1.54 eV with an absorption coefficient of 4x104cm-1. A solar cell utilizing PLD grown CZTS with the structure SLG/Mo/CZTS/CdS/ZnO/ITO showed a conversion efficiency of 5.85% with Voc = 376 mV, Jsc = 38.9 mA/cm2 and Fill Factor, FF = 0.40.

Wettability modification of porous PET by atmospheric femtosecond PLD

NASA Astrophysics Data System (ADS)

Assaf, Youssef; Forstmann, Guillaume; Kietzig, Anne-Marie

2018-04-01

In this study, porous structures were created on poly(ethylene terephthalate) (PET) by femtosecond (fs) laser micromachining. While such structures offer a texture that is desirable for several applications, their wettability does not always match the application in question. The aim of this investigation is to tune the wettability of such surfaces by incorporating a controlled amount of nanoparticles into the structure. The machined PET samples were thus used as substrates for fs pulsed laser deposition (PLD) of titanium under ambient conditions. The nanoparticles were deposited as nanochain clusters due to the formation of an oxide layer between individual nanoparticles. The stability of nanoparticle incorporation was tested by placing the samples in an ultrasonic ethanol bath. Results indicated that nanoparticles were still successfully incorporated into the microstructure after sonication. Nanoparticle surface coverage was observed to be controllable through the operating fluence. The dynamic contact angles of the resulting composite surface were observed to decrease with increasing titanium incorporation. Therefore, this work highlights atmospheric fs PLD as a method for wettability modification of high surface area microstructures without undermining their topology. In addition, this technique uses almost the same equipment as the machining process by which the microstructures are initially created, further highlighting its practicality.

Special-purpose computer for holography HORN-4 with recurrence algorithm

NASA Astrophysics Data System (ADS)

Shimobaba, Tomoyoshi; Hishinuma, Sinsuke; Ito, Tomoyoshi

2002-10-01

We designed and built a special-purpose computer for holography, HORN-4 (HOlographic ReconstructioN) using PLD (Programmable Logic Device) technology. HORN computers have a pipeline architecture. We use HORN-4 as an attached processor to enhance the performance of a general-purpose computer when it is used to generate holograms using a "recurrence formulas" algorithm developed by our previous paper. In the HORN-4 system, we designed the pipeline by adopting our "recurrence formulas" algorithm which can calculate the phase on a hologram. As the result, we could integrate the pipeline composed of 21 units into one PLD chip. The units in the pipeline consists of one BPU (Basic Phase Unit) unit and twenty CU (Cascade Unit) units. These CU units can compute twenty light intensities on a hologram plane at one time. By mounting two of the PLD chips on a PCI (Peripheral Component Interconnect) universal board, HORN-4 can calculate holograms at high speed of about 42 Gflops equivalent. The cost of HORN-4 board is about 1700 US dollar. We could obtain 800×600 grids hologram from a 3D-image composed of 415 points in about 0.45 sec with the HORN-4 system.

Growth of Ferromagnetic Epitaxial Film of Hexagonal FeGe on (111) Ge Surface

NASA Astrophysics Data System (ADS)

Kumar, Dushyant; Joshi, P. C.; Hossain, Z.; Budhani, R. C.

2014-03-01

The realization of semiconductors showing ferromagnetic order at easily accessible temperatures has been of interest due to their potential use in spintronic devices where long spin life times are of key interest. We have realized the growth of FeGe thin films on Ge (111) wafers using pulsed laser deposition (PLD). The stoichiometric and single phase FeGe target used in PLD chamber has been made by arc melting. A typical θ-2 θ diffraction spectra performed on 40 nm thick FeGe film suggests the stabilization of β-Ni2In (B82-type) hexagonal phase with an epitaxial orientation of (0001)FeGe ||(111)Ge and [11-20]FeGe ||[-110]Ge. SEM images shows a granular structure with the formation of very large grains of about 100 to 500 nm in lateral dimension. The magnetization vs. temperature data taken from SQUID reveal the TC of ~ 270K. Since, PLD technique makes it easier to stabilize the B82 (Ni2In) hexagonal phase in thin FeGe films, this work opens opportunities to reinvestigate many conflicting results on various properties of the FeGe system.

Folding Behaviors of Protein (Lysozyme) Confined in Polyelectrolyte Complex Micelle.

PubMed

Wu, Fu-Gen; Jiang, Yao-Wen; Chen, Zhan; Yu, Zhi-Wu

2016-04-19

The folding/unfolding behavior of proteins (enzymes) in confined space is important for their properties and functions, but such a behavior remains largely unexplored. In this article, we reported our finding that lysozyme and a double hydrophilic block copolymer, methoxypoly(ethylene glycol)5K-block-poly(l-aspartic acid sodium salt)10 (mPEG(5K)-b-PLD10), can form a polyelectrolyte complex micelle with a particle size of ∼30 nm, as verified by dynamic light scattering and transmission electron microscopy. The unfolding and refolding behaviors of lysozyme molecules in the presence of the copolymer were studied by microcalorimetry and circular dichroism spectroscopy. Upon complex formation with mPEG(5K)-b-PLD10, lysozyme changed from its initial native state to a new partially unfolded state. Compared with its native state, this copolymer-complexed new folding state of lysozyme has different secondary and tertiary structures, a decreased thermostability, and significantly altered unfolding/refolding behaviors. It was found that the native lysozyme exhibited reversible unfolding and refolding upon heating and subsequent cooling, while lysozyme in the new folding state (complexed with the oppositely charged PLD segments of the polymer) could unfold upon heating but could not refold upon subsequent cooling. By employing the heating-cooling-reheating procedure, the prevention of complex formation between lysozyme and polymer due to the salt screening effect was observed, and the resulting uncomplexed lysozyme regained its proper unfolding and refolding abilities upon heating and subsequent cooling. Besides, we also pointed out the important role the length of the PLD segment played during the formation of micelles and the monodispersity of the formed micelles. Furthermore, the lysozyme-mPEG(5K)-b-PLD10 mixtures prepared in this work were all transparent, without the formation of large aggregates or precipitates in solution as frequently observed in other protein-polyelectrolyte systems. Hence, the present protein-PEGylated poly(amino acid) mixture provides an ideal water-soluble model system to study the important role of electrostatic interaction in the complexation between proteins and polymers, leading to important new knowledge on the protein-polymer interactions. Moreover, the polyelectrolyte complex micelle formed between protein and PEGylated polymer may provide a good drug delivery vehicle for therapeutic proteins.

Transarterial Embolization for Treatment of Symptomatic Polycystic Liver Disease: More than 2-year Follow-up

PubMed Central

Zhang, Jin-Long; Yuan, Kai; Wang, Mao-Qiang; Yan, Jie-Yu; Xin, Hai-Nan; Wang, Yan; Liu, Feng-Yong; Bai, Yan-Hua; Wang, Zhi-Jun; Duan, Feng; Fu, Jin-Xin

2017-01-01

Background: Currently, treatment of symptomatic polycystic liver disease (PLD) is still a challenging problem, especially for these patients who are not feasible for surgery. Minimally invasive options such as laparoscopic fenestration and percutaneous cyst aspiration with sclerotherapy demonstrated disappointing results due to multiple lesions. Because the cysts in PLD are mostly supplied from hepatic arteries but not from portal veins, transcatheter arterial embolization (TAE) of the hepatic artery branches that supply the major hepatic cysts can lead to shrinkage of the cyst and liver size, relieve symptoms, and improve nutritional status. This study aimed to evaluate the effectiveness of TAE with a mixture of N-butyl-2-cyanoacrylate (NBCA) and iodized oil for patients with severe symptomatic PLD during a more than 2-year follow-up. Methods: Institutional review board had approved this study. Written informed consent was obtained from all patients. From February 2007 to December 2014, twenty-three patients (20 women and 3 men; mean age, 49.0 ± 14.5 years) infeasible for surgical treatments underwent TAE. Changes in the abdominal circumferences, volumes of intrahepatic cysts, hepatic parenchyma volume, and whole liver, clinical symptoms, laboratory data, and complications were evaluated after TAE. Results: Technical success was achieved in all cases. No procedure-related major complications occurred. The median follow-up period after TAE was 48.5 months (interquartile range, 30.0–72.0 months). PLD-related severe symptoms were improved remarkably in 86% of the treated patients; TAE failed to benefit in four patients (four patients did not benefit from TAE). The mean maximum abdominal circumference decreased significantly from 106.0 ± 8.0 cm to 87.0 ± 15.0 cm (P = 0.021). The mean intrahepatic cystic volume reduction rates compared with pre-TAE were 36% at 12 months, 37% at 24 months, and 38% at 36 months after TAE (P < 0.05). The mean liver volume reduction rates were 32% at 12 months, 31% at 24 months, and 33% at 36 months (P < 0.05). Conclusions: TAE with the mixture of NBCA and iodized oil appears to be a safe and effective treatment method for patients with symptomatic PLD, especially for those who are not good candidates for surgical treatments, to improve both hepatic volume and hepatic cysts volume. PMID:28776546

GnRH signalling pathways and GnRH-induced homologous desensitization in a gonadotrope cell line (alphaT3-1).

PubMed

Poulin, B; Rich, N; Mas, J L; Kordon, C; Enjalbert, A; Drouva, S V

1998-07-25

Exposure of the gonadotrope cells to gonadotropin-releasing hormone (GnRH) reduces their responsiveness to a new GnRH stimulation (homologous desensitization). The time frame as well as the mechanisms underlying this phenomenon are yet unclear. We studied in a gonadotrope cell line (alphaT3-1) the effects of short as well as long term GnRH pretreatments on the GnRH-induced phospholipases-C (PLC), -A2 (PLA2) and -D (PLD) activities, by measuring the production of IP3, total inositol phosphates (IPs), arachidonic acid (AA) and phosphatidylethanol (PEt) respectively. We demonstrated that although rapid desensitization of GnRH-induced IP3 formation did not occur in these cells, persistent stimulation of cells with GnRH or its analogue resulted in a time-dependent attenuation of GnRH-elicited IPs formation. GnRH-induced IPs desensitization was potentiated after direct activation of PKC by the phorbol ester TPA, suggesting the involvement of distinct mechanisms in the uncoupling exerted by either GnRH or TPA on GnRH-stimulated PI hydrolysis. The levels of individual phosphoinositides remained unchanged under any desensitization condition applied. Interestingly, while the GnRH-induced PLA2 activity was rapidly desensitized (2.5 min) after GnRH pretreatments, the neuropeptide-evoked PLD activation was affected at later times, indicating an important time-dependent contribution of these enzymatic activities in the sequential events underlying the GnRH-induced homologous desensitization processes in the gonadotropes. Under GnRH desensitization conditions, TPA was still able to induce PLD activation and to further potentiate the GnRH-evoked PLD activity. AlphaT3-1 cells possess several PKC isoforms which, except PKCzeta, were differentially down-regulated by TPA (PKCalpha, betaII, delta, epsilon, eta) or GnRH (PKCbetaII, delta, epsilon, eta). In spite of the presence of PKC inhibitors or down-regulation of PKC isoforms by TPA, the desensitizing effect of the neuropeptide on GnRH-induced IPs, AA and PEt formation remained unchanged. In conclusion, in alphaT3-1 cells the GnRH-induced homologous desensitization affects the GnRH coupling with PLC, PLA2 and PLD by mechanism(s) which do not implicate TPA-sensitive PKC isoforms, but likely reflect time-dependent modification(s) on the activation processes of the enzymes.

Ursodeoxycholic acid in advanced polycystic liver disease: A phase 2 multicenter randomized controlled trial.

PubMed

D'Agnolo, Hedwig M A; Kievit, Wietske; Takkenberg, R Bart; Riaño, Ioana; Bujanda, Luis; Neijenhuis, Myrte K; Brunenberg, Ellen J L; Beuers, Ulrich; Banales, Jesus M; Drenth, Joost P H

2016-09-01

Ursodeoxycholic acid (UDCA) inhibits proliferation of polycystic human cholangiocytes in vitro and hepatic cystogenesis in a rat model of polycystic liver disease (PLD) in vivo. Our aim was to test whether UDCA may beneficially affect liver volume in patients with advanced PLD. We conducted an international, multicenter, randomized controlled trial in symptomatic PLD patients from three tertiary referral centers. Patients with PLD and total liver volume (TLV) ⩾2500ml were randomly assigned to UDCA treatment (15-20mg/kg/day) for 24weeks, or to no treatment. Primary endpoint was proportional change in TLV. Secondary endpoints were change in symptoms and health-related quality of life. We performed a post-hoc analysis of the effect of UDCA on liver cyst volume (LCV). We included 34 patients and were able to assess primary endpoint in 32 patients, 16 with autosomal dominant polycystic kidney disease (ADPKD) and 16 with autosomal dominant polycystic liver disease (ADPLD). Proportional TLV increased by 4.6±7.7% (mean TLV increased from 6697ml to 6954ml) after 24weeks of UDCA treatment compared to 3.1±3.8% (mean TLV increased from 5512ml to 5724ml) in the control group (p=0.493). LCV was not different after 24weeks between controls and UDCA treated patients (p=0.848). However, UDCA inhibited LCV growth in ADPKD patients compared to ADPKD controls (p=0.049). UDCA administration for 24weeks did not reduce TLV in advanced PLD, but UDCA reduced LCV growth in ADPKD patients. Future studies might explore whether ADPKD and ADPLD patients respond differently to UDCA treatment. Current therapies for polycystic liver disease are invasive and have high recurrence risks. Our trial showed that the drug, ursodeoxycholic acid, was not able to reduce liver volume in patients with polycystic liver disease. However, a subgroup analysis in patients that have kidney cysts as well showed that liver cyst volume growth was reduced in patients who received ursodeoxycholic acid in comparison to patients who received no treatment. Trial registration number https://www.clinicaltrials.gov/: NCT02021110. EudraCT Number https://www.clinicaltrialsregister.eu/: 2013-003207-19. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Stress peptide PACAP engages multiple signaling pathways within the carotid body to initiate excitatory responses in respiratory and sympathetic chemosensory afferents.

PubMed

Roy, Arijit; Derakhshan, Fatemeh; Wilson, Richard J A

2013-06-15

Consistent with a critical role in respiratory and autonomic stress responses, the carotid bodies are strongly excited by pituitary adenylate cyclase-activating polypeptide (PACAP), a neuropeptide implicated in stress responses throughout the sympathetic nervous system. PACAP excites isolated carotid body glomus cells via activation of PAC1 receptors, with one study suggesting PAC1-induced excitation is due entirely to protein kinase A (PKA)-mediated inhibition of TASK channels. However, in other systems, PAC1 is known to be coupled to multiple intracellular signaling pathways, including PKA, phospholipase C (PLC), phospholipase D (PLD), and protein kinase C (PKC), that trigger multiple downstream effectors including increased Ca²⁺ mobilization, inhibition of various K⁺ channels, and activation of nonselective cation channels. This study tests if non-PKA/TASK channel signaling helps mediate the stimulatory effects of PACAP on the carotid body. Using an ex vivo arterially perfused rat carotid body preparation, we show that PACAP-38 stimulates carotid sinus nerve activity in a biphasic manner (peak response, falling to plateau). PKA blocker H-89 only reduced the plateau response (~41%), whereas the TASK-1-like K⁺ channel blocker/transient receptor potential vanilloid 1 channel agonist anandamide only inhibited the peak response (~48%), suggesting involvement of additional pathways. The PLD blocker CAY10594 significantly inhibited both peak and plateau responses. The PLC blocker U73122 decimated both peak and plateau responses. Brefeldin A, a blocker of Epac (cAMP-activated guanine exchange factor, reported to link Gs-coupled receptors with PLC/PLD), also reduced both phases of the response, as did blocking signaling downstream of PLC/PLD with the PKC inhibitors chelerythrine chloride and GF109203X. Suggesting the involvement of non-TASK ion channels in the effects of PACAP, the A-type K⁺ channel blocker 4-aminopyridine, and the putative transient receptor potential channel (TRPC)/T-type calcium channel blocker SKF96365 each significantly inhibited the peak and steady-state responses. These data suggest the stimulatory effect of PACAP-38 on carotid body sensory activity is mediated through multiple signaling pathways: the PLC-PKC pathways predominates, with TRPC and/or T-type channel activation and Kv channel inactivation; only partial involvement is attributable to PKA and PLD activation.

DNA Damage and Repair in Human Cancer: Molecular Mechanisms and Contribution to Therapy-Related Leukemias

PubMed Central

Casorelli, Ida; Bossa, Cecilia; Bignami, Margherita

2012-01-01

Most antitumour therapies damage tumour cell DNA either directly or indirectly. Without repair, damage can result in genetic instability and eventually cancer. The strong association between the lack of DNA damage repair, mutations and cancer is dramatically demonstrated by a number of cancer-prone human syndromes, such as xeroderma pigmentosum, ataxia-telangiectasia and Fanconi anemia. Notably, DNA damage responses, and particularly DNA repair, influence the outcome of therapy. Because DNA repair normally excises lethal DNA lesions, it is intuitive that efficient repair will contribute to intrinsic drug resistance. Unexpectedly, a paradoxical relationship between DNA mismatch repair and drug sensitivity has been revealed by model studies in cell lines. This suggests that connections between DNA repair mechanism efficiency and tumour therapy might be more complex. Here, we review the evidence for the contribution of carcinogenic properties of several drugs as well as of alterations in specific mechanisms involved in drug-induced DNA damage response and repair in the pathogenesis of therapy-related cancers. PMID:23066388

PARP1 inhibitor olaparib (Lynparza) exerts synthetic lethal effect against ligase 4-deficient melanomas

PubMed Central

Czyż, Małgorzata; Toma, Monika; Gajos-Michniewicz, Anna; Majchrzak, Kinga; Hoser, Grazyna; Szemraj, Janusz; Nieborowska-Skorska, Margaret; Cheng, Phil; Gritsyuk, Daniel; Levesque, Mitchell; Dummer, Reinhard; Sliwinski, Tomasz; Skorski, Tomasz

2016-01-01

Cancer including melanoma may be “addicted” to double strand break (DSB) repair and targeting this process could sensitize them to the lethal effect of DNA damage. PARP1 exerts an important impact on DSB repair as it binds to both single- and double- strand breaks. PARP1 inhibitors might be highly effective drugs triggering synthetic lethality in patients whose tumors have germline or somatic defects in DNA repair genes. We hypothesized that PARP1-dependent synthetic lethality could be induced in melanoma cells displaying downregulation of DSB repair genes. We observed that PARP1 inhibitor olaparib sensitized melanomas with reduced expression of DNA ligase 4 (LIG4) to an alkylatimg agent dacarbazine (DTIC) treatment in vitro, while normal melanocytes remained intact. PARP1 inhibition caused accumulation of DSBs, which was associated with apoptosis in LIG4 deficient melanoma cells. Our hypothesis that olaparib is synthetic lethal with LIG4 deficiency in melanoma cells was supported by selective anti-tumor effects of olaparib used either alone or in combination with dacarbazine (DTIC) in LIG4 deficient, but not LIG4 proficient cells. In addition, olaparib combined with DTIC inhibited the growth of LIG4 deficient human melanoma xenografts. This work for the first time demonstrates the effectiveness of a combination of PARP1 inhibitor olaparib and alkylating agent DTIC for treating LIG4 deficient melanomas. In addition, analysis of the TCGA and transcriptome microarray databases revealed numerous individual melanoma samples potentially displaying specific defects in DSB repair pathways, which may predispose them to synthetic lethality triggered by PARP1 inhibitor combined with a cytotoxic drug. PMID:27705909

Unmanned Air Vehicle/Remotely Piloted Vehicle Analysis for Lethal UAV/ RPV

DTIC Science & Technology

1993-09-01

taking the output power at a relatively low speed from the camshaft which is gear-driven at half the crankshaft RPM [Ref. 6]. there engine is a four...from the top of a tree , from over a steep cliff, or other perilous terrain. In addition, parachute landings invariably take their toll in vehicle damage

Periscopic Spine Surgery

DTIC Science & Technology

2007-01-01

radiation therapy In radiation therapy , the overarching goal is to deliver a lethal dose to the cancerous tissue while minimizing collateral damage to the ...Computer is shown in Figure 6. The exercise protocol is first parsed into a control mode based on the desired activation of configuration space variables...ABSTRACT In this paper, we present the design and implementation of a

Natural history of thyroid cancer [Review].

PubMed

Takano, Toru

2017-03-31

Thyroid cancers have long been considered to arise in middle age and, after their repeated proliferation, resulting in further damage to the genome, they progress to more aggressive and lethal cancers. However, in 2014, some studies were reported that might lead to a marked change in our understanding of the natural history of thyroid cancer. A high prevalence of papillary carcinoma in the young suggested that the first initiation of thyroid cancer is likely to occur in the infantile period. Such a conclusion was also supported by a very slow growth rate of papillary microcarcinomas (PMCs) in an observation trial. The proliferation rate of PMCs was negatively correlated with the age, and surgery to remove PMCs did not contribute to reduce mortality from thyroid cancer. These findings strongly suggested the existence of self-limiting cancers, which are truly malignant but do not progress to lethal cancers, for the first time in human history. The early detection of self-limiting cancers results in overdiagnosis. Ultrasonographic screening of the thyroid in the young should be avoided. Lethal thyroid cancers, whose origin is still unknown, appear suddenly after middle age. In the elderly, thyroid cancers are a mixture of self-limiting and lethal cancers; thus, when thyroid cancer is detected, careful follow-up with examination of its growth rate is required.

Immunopathology of highly virulent pathogens: insights from Ebola virus.

PubMed

Zampieri, Carisa A; Sullivan, Nancy J; Nabel, Gary J

2007-11-01

Ebola virus is a highly virulent pathogen capable of inducing a frequently lethal hemorrhagic fever syndrome. Accumulating evidence indicates that the virus actively subverts both innate and adaptive immune responses and triggers harmful inflammatory responses as it inflicts direct tissue damage. The host immune system is ultimately overwhelmed by a combination of inflammatory factors and virus-induced cell damage, particularly in the liver and vasculature, often leading to death from septic shock. We summarize the mechanisms of immune dysregulation and virus-mediated cell damage in Ebola virus-infected patients. Future approaches to prevention and treatment of infection will be guided by answers to unresolved questions about interspecies transmission, molecular mechanisms of pathogenesis, and protective adaptive and innate immune responses to Ebola virus.

Why is intracellular ice lethal? A microscopical study showing evidence of programmed cell death in cryo-exposed embryonic axes of recalcitrant seeds of Acer saccharinum.

PubMed

Wesley-Smith, James; Walters, Christina; Pammenter, N W; Berjak, Patricia

2015-05-01

Conservation of the genetic diversity afforded by recalcitrant seeds is achieved by cryopreservation, in which excised embryonic axes (or, where possible, embryos) are treated and stored at temperatures lower than -180 °C using liquid nitrogen. It has previously been shown that intracellular ice forms in rapidly cooled embryonic axes of Acer saccharinum (silver maple) but this is not necessarily lethal when ice crystals are small. This study seeks to understand the nature and extent of damage from intracellular ice, and the course of recovery and regrowth in surviving tissues. Embryonic axes of A. saccharinum, not subjected to dehydration or cryoprotection treatments (water content was 1·9 g H2O g(-1) dry mass), were cooled to liquid nitrogen temperatures using two methods: plunging into nitrogen slush to achieve a cooling rate of 97 °C s(-1) or programmed cooling at 3·3 °C s(-1). Samples were thawed rapidly (177 °C s(-1)) and cell structure was examined microscopically immediately, and at intervals up to 72 h in vitro. Survival was assessed after 4 weeks in vitro. Axes were processed conventionally for optical microscopy and ultrastructural examination. Immediately following thaw after cryogenic exposure, cells from axes did not show signs of damage at an ultrastructural level. Signs that cells had been damaged were apparent after several hours of in vitro culture and appeared as autophagic decomposition. In surviving tissues, dead cells were sloughed off and pockets of living cells were the origin of regrowth. In roots, regrowth occurred from the ground meristem and procambium, not the distal meristem, which became lethally damaged. Regrowth of shoots occurred from isolated pockets of surviving cells of peripheral and pith meristems. The size of these pockets may determine the possibility for, the extent of and the vigour of regrowth. Autophagic degradation and ultimately autolysis of cells following cryo-exposure and formation of small (0·2-0·4 µm) intracellular ice crystals challenges current ideas that ice causes immediate physical damage to cells. Instead, freezing stress may induce a signal for programmed cell death (PCD). Cells that form more ice crystals during cooling have faster PCD responses. Published by Oxford University Press on behalf of the Annals of Botany Company 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Evaluation of less-lethal characteristics of a chemical delivery system for use by prison and corrections departments

NASA Astrophysics Data System (ADS)

Cuadros, Jaime H.

1998-12-01

The use of high pressure water streams to disperse crowds, in general, and to subdue unruly individuals in a prison environment has been shown to be an effective way to reduce the severity of the confrontations among the inmates and guards. The less lethal chemical delivery system (Hydro-Force) disperses chemicals, such as oleoresin capsicum or 'pepper spray' (OC), in the high pressure water stream. The high pressure water stream is aimed to impact the target individuals. A close miss overhead is still very effective as the water mixture can 'ran' on them and soak the target individuals. The effect of the OC is multiplied by the whole body exposure with excellent results in stopping any undesirable behavior of the target individuals, without bodily contact or struggle with the guards. The possibility of producing blunt trauma damage by the impact of the water stream, at close range, was a concern to be investigated. The water stream can be considered as a special fluid kinetic energy projectile. At impact, the kinetic energy of the mass and velocity of the stream of water is dissipated and its momentum is transferred to the target. The purpose of this cursory study is to evaluate whether the physiological effects of this impact is below the threshold of damage or lethality. Comparisons are made, where the two crucial elements, the force coupled to the target and the duration of its application, in order to establish the probably level of blunt trauma associated with the use of the water jet.

Antibiotics induce redox-related physiological alterations as part of their lethality

PubMed Central

Dwyer, Daniel J.; Belenky, Peter A.; Yang, Jason H.; MacDonald, I. Cody; Martell, Jeffrey D.; Takahashi, Noriko; Chan, Clement T. Y.; Lobritz, Michael A.; Braff, Dana; Schwarz, Eric G.; Ye, Jonathan D.; Pati, Mekhala; Vercruysse, Maarten; Ralifo, Paul S.; Allison, Kyle R.; Khalil, Ahmad S.; Ting, Alice Y.; Walker, Graham C.; Collins, James J.

2014-01-01

Deeper understanding of antibiotic-induced physiological responses is critical to identifying means for enhancing our current antibiotic arsenal. Bactericidal antibiotics with diverse targets have been hypothesized to kill bacteria, in part by inducing production of damaging reactive species. This notion has been supported by many groups but has been challenged recently. Here we robustly test the hypothesis using biochemical, enzymatic, and biophysical assays along with genetic and phenotypic experiments. We first used a novel intracellular H2O2 sensor, together with a chemically diverse panel of fluorescent dyes sensitive to an array of reactive species to demonstrate that antibiotics broadly induce redox stress. Subsequent gene-expression analyses reveal that complex antibiotic-induced oxidative stress responses are distinct from canonical responses generated by supraphysiological levels of H2O2. We next developed a method to quantify cellular respiration dynamically and found that bactericidal antibiotics elevate oxygen consumption, indicating significant alterations to bacterial redox physiology. We further show that overexpression of catalase or DNA mismatch repair enzyme, MutS, and antioxidant pretreatment limit antibiotic lethality, indicating that reactive oxygen species causatively contribute to antibiotic killing. Critically, the killing efficacy of antibiotics was diminished under strict anaerobic conditions but could be enhanced by exposure to molecular oxygen or by the addition of alternative electron acceptors, indicating that environmental factors play a role in killing cells physiologically primed for death. This work provides direct evidence that, downstream of their target-specific interactions, bactericidal antibiotics induce complex redox alterations that contribute to cellular damage and death, thus supporting an evolving, expanded model of antibiotic lethality. PMID:24803433

A Translational Murine Model of Sub-Lethal Intoxication with Shiga Toxin 2 Reveals Novel Ultrastructural Findings in the Brain Striatum

PubMed Central

Tironi-Farinati, Carla; Geoghegan, Patricia A.; Cangelosi, Adriana; Pinto, Alipio; Loidl, C. Fabian; Goldstein, Jorge

2013-01-01

Infection by Shiga toxin-producing Escherichia coli causes hemorrhagic colitis, hemolytic uremic syndrome (HUS), acute renal failure, and also central nervous system complications in around 30% of the children affected. Besides, neurological deficits are one of the most unrepairable and untreatable outcomes of HUS. Study of the striatum is relevant because basal ganglia are one of the brain areas most commonly affected in patients that have suffered from HUS and since the deleterious effects of a sub-lethal dose of Shiga toxin have never been studied in the striatum, the purpose of this study was to attempt to simulate an infection by Shiga toxin-producing E. coli in a murine model. To this end, intravenous administration of a sub-lethal dose of Shiga toxin 2 (0.5 ηg per mouse) was used and the correlation between neurological manifestations and ultrastructural changes in striatal brain cells was studied in detail. Neurological manifestations included significant motor behavior abnormalities in spontaneous motor activity, gait, pelvic elevation and hind limb activity eight days after administration of the toxin. Transmission electron microscopy revealed that the toxin caused early perivascular edema two days after administration, as well as significant damage in astrocytes four days after administration and significant damage in neurons and oligodendrocytes eight days after administration. Interrupted synapses and mast cell extravasation were also found eight days after administration of the toxin. We thus conclude that the chronological order of events observed in the striatum could explain the neurological disorders found eight days after administration of the toxin. PMID:23383285

Pulsed laser deposition and characterization of cellulase thin films

NASA Astrophysics Data System (ADS)

Cicco, N.; Morone, A.; Verrastro, M.; Viggiano, V.

2013-08-01

Thin films of cellulase were obtained by pulsed laser deposition (PLD) on an appropriate substrate. Glycoside hydrolase cellulase has received our attention because it emerges among the antifouling enzymes (enzymes being able to remove and prevent the formation of micro-organism biofilms) used in industry and medicine field. Pressed cellulase pellets, used as target material, were ablated with pulses of a Nd-YAG laser working at wavelength of 532 nm. In this work, we evaluated the impact of PLD technique both on molecular structure and hydrolytic activity of cellulase. Characteristic chemical bonds and morphology of deposited layers were investigated by FTIR spectroscopy and SEM respectively. The hydrolytic activity of cellulase thin films was detected by a colorimetric assay.

A practical topological insulator saturable absorber for mode-locked fiber laser

PubMed Central

Yan, Peiguang; Lin, Rongyong; Ruan, Shuangchen; Liu, Aijiang; Chen, Hao; Zheng, Yuequn; Chen, Sifan; Guo, Chunyu; Hu, Juguang

2015-01-01

A novel saturable absorber (SA) was fabricated by coating the topological insulator (TI) film on microfiber using pulsed laser deposition (PLD) method. The TISA device had an insertion loss of ~1.25 dB, a saturable intensity of 26.7 MW/cm2, a modulation depth of ~5.7%, and a nonsaturable loss of 20.5%. Upon employing this SA device, we established a passively mode-locked EDFL and achieved nearly free-chirped soliton pulse with 286 fs of pulse duration and >73 dB of signal to noise ratio (SNR). This result clearly evidences that the PLD is an effective scheme for practical SA device fabrication. PMID:25732598

Designing Trojan Horses | Center for Cancer Research

Cancer.gov

Waging battle against cancer cells without inflicting damage on normal tissue has long been a goal for cancer treatment. A new type of drug called immunotoxins may help make this goal a reality. Much like the Greeks used a wooden horse to get soldiers inside the gates of Troy, immunotoxins use clever genetic engineering to get a lethal toxin inside cancer cells. Each

Precision Strike Annual Programs Review

DTIC Science & Technology

2009-03-11

Deceleration and Stabilization Subsystem Squib Fire Unit Thermal Battery Electronic Safe and Arm Device Air Data Sensor Main ChargeControl Actuator Power ...platforms, and ground teams. • Powered , maneuverable, small, lightweight, accurate and lethal, with reduced risk of collateral damage. Raytheon Missile...requirements evolve, so will capability • Builds on powerful infrastructure • “Color of Money” timing is very different Traditional Approach Traditional IOC

Aircraft Survivability: Vulnerability Reduction, Spring 2006

DTIC Science & Technology

2006-01-01

selected small arms, rocket propelled grenades, and shoulder-fired missiles will be presented. Figure 1 and Figure 2 illustrate previous demonstrations...lethality. Hands-on experience will be provided with threat munitions and missiles , test articles, damaged-air- craft hardware, live fire...non-linear effects of scale and operational environment. Current Efforts In the structures S&T program at the US Army Aviation and Missile Research

Local inflammation, lethality and cytokine release in mice injected with Bothrops atrox venom.

PubMed Central

Barros, S F; Friedlanskaia, I; Petricevich, V L; Kipnis, T L

1998-01-01

We have provided evidence that: (a) lethality of mice to crude Bothrops venom varies according the isogenic strain (A/J > C57Bl/6 > A/Sn > BALB/c > C3H/HePas > DBA/2 > C3H/He); (b)BALB/c mice (LD50=100.0 microg) were injected i.p. with 50 microg of venom produced IL-6, IL-10, INF-gamma, TNF-alpha and NO in the serum. In vitro the cells from the mice injected and challenged with the venom only released IL-10 while peritoneal macrophages released IL-10, INF-gamma and less amounts of IL-6; (c) establishment of local inflammation and necrosis induced by the venom, coincides with the peaks of TNF-alpha, IFN-gamma and NO and the damage was neutralized when the venom was incubated with a monoclonal antibody against a 60 kDa haemorrhagic factor. These results suggest that susceptibility to Bothrops atrox venom is genetically dependent but MHC independent; that IL-6, IL-10, TNF-alpha, IFN-gamma and NO can be involved in the mediation of tissue damage; and that the major venom component inducers of the lesions are haemorrhagins. PMID:9883969

Anaerobic Killing of Oral Streptococci by Reduced, Transition Metal Cations

PubMed Central

Dunning, J. C.; Ma, Y.; Marquis, R. E.

1998-01-01

Reduced, transition metal cations commonly enhance oxidative damage to cells caused by hydroperoxides formed as a result of oxygen metabolism or added externally. As expected, the cations Fe2+ and Cu+ enhanced killing of Streptococcus mutans GS-5 by hydroperoxides. However, unexpectedly, they also induced lethal damage under fully anaerobic conditions in a glove box with no exposure to O2 or hydroperoxides from initial treatment with the cations. Sensitivities to anaerobic killing by Fe2+ varied among the organisms tested. The oral streptococci Streptococcus gordonii ATCC 10558, Streptococcus rattus FA-1, and Streptococcus sanguis NCTC 10904 were approximately as sensitive as S. mutans GS-5. Enterococcus hirae ATCC 9790, Actinomyces viscosus OMZ105E, and Actinomyces naeslundii WVU45 had intermediate sensitivity, while Lactobacillus casei ATCC 4646 and Escherichia coli B were insensitive. Killing of S. mutans GS-5 in response to millimolar levels of added Fe2+ occurred over a wide range of temperatures and pH. The organism was able to take up ferrous iron, but ferric reductase activity could not be detected. Chelators, uric acid, and thiocyanate were not effective inhibitors of the lethal damage. Sulfhydryl compounds, ferricyanide, and ferrocyanide were protective if added prior to Fe2+ exposure. Fe2+, but not Fe3+, acted to reduce the acid tolerance of glycolysis by intact cells of S. mutans. The reduction in acid tolerance appeared to be related directly to Fe2+ inhibition of F-ATPase, which could be assayed with permeabilized cells, isolated membranes, or F1 enzyme separated from membranes. Cu+ and Cu2+ also inhibited F-ATPase and sensitized glycolysis by intact cells to acid. All of these damaging actions occurred anaerobically and thus did not appear to involve reactive oxygen species. PMID:9435058

In-vivo optical imaging of hsp70 expression to assess collateral tissue damage associated with infrared laser ablation of skin

PubMed Central

Wilmink, Gerald J.; Opalenik, Susan R.; Beckham, Joshua T.; Mackanos, Mark A.; Nanney, Lillian B.; Contag, Christopher H.; Davidson, Jeffrey M.; Jansen, E. Duco

2013-01-01

Laser surgical ablation is achieved by selecting laser parameters that remove confined volumes of target tissue and cause minimal collateral damage. Previous studies have measured the effects of wavelength on ablation, but neglected to measure the cellular impact of ablation on cells outside the lethal zone. In this study, we use optical imaging in addition to conventional assessment techniques to evaluate lethal and sublethal collateral damage after ablative surgery with a free-electron laser (FEL). Heat shock protein (HSP) expression is used as a sensitive quantitative marker of sublethal damage in a transgenic mouse strain, with the hsp70 promoter driving luciferase and green fluorescent protein (GFP) expression (hsp70A1-L2G). To examine the wavelength dependence in the mid-IR, laser surgery is conducted on the hsp70A1-L2G mouse using wavelengths targeting water (OH stretch mode, 2.94 μm), protein (amide-II band, 6.45 μm), and both water and protein (amide-I band, 6.10 μm). For all wavelengths tested, the magnitude of hsp70 expression is dose-dependent and maximal 5 to 12 h after surgery. Tissues treated at 6.45 μm have approximately 4× higher hsp70 expression than 6.10 μm. Histology shows that under comparable fluences, tissue injury at the 2.94-μm wavelength was 2× and 3× deeper than 6.45 and 6.10 μm, respectively. The 6.10-μm wavelength generates the least amount of epidermal hyperplasia. Taken together, this data suggests that the 6.10-μm wavelength is a superior wavelength for laser ablation of skin. PMID:19021444

Nutritional supplement chromium picolinate causes sterility and lethal mutations in Drosophila melanogaster

PubMed Central

Hepburn, Dion D. D.; Xiao, Jiarong; Bindom, Sharell; Vincent, John B.; O'Donnell, Janis

2003-01-01

The nutritional dietary supplement chromium picolinate, [Cr(pic)3], has gained much notoriety as a safe supplement that supposedly promotes fat loss and muscle enhancement in humans. Thus, a significant industry has materialized around the incorporation of [Cr(pic)3] in many sports foods and drinks and a variety of weight loss products. However, in vitro studies have suggested that low levels of [Cr(pic)3] in the presence of biological reducing agents can catalytically generate reactive oxygen species, and recent in vivo studies have detected oxidative damage in rats receiving the supplement. The potential deleterious in vivo effects of this activity were examined by using Drosophila melanogaster. [Cr(pic)3], but not CrCl3, at levels of 260 μg Cr/kg food or less were found to lower the success rate of pupation and eclosion and to arrest development of pupae in a concentration dependent fashion. X-linked lethal analysis indicates that the supplement greatly enhances the rate of appearance of lethal mutations and dominant female sterility. PMID:12649323

Consequences of Lethal-Whole-Body Gamma Radiation and Possible Ameliorative Role of Melatonin

PubMed Central

Mihandoost, Ehsan; Shirazi, Alireza; Mahdavi, Seied Rabie; Aliasgharzadeh, Akbar

2014-01-01

Gamma radiation induces the generation of free radicals, leading to serious cellular damages in biological systems. Radioprotectors act as prophylactic agents that are administered to shield normal cells and tissues from the deleterious effects of radiation. Melatonin synergistically acts as an immune-stimulator and antioxidant. We investigated the possible radioprotective role of melatonin (100 mg/kg i.p.) against lethal-whole-body radiation- (10 Gy) induced sickness, body weight loss, and mortality in rats. Results of the present study suggest that exposure to lethal-whole-body radiation incurred mortality, body weight loss, and apoptosis and it also depleted the immunity and the antioxidant status of the rats. Our results show that melatonin pretreatment provides protection against radiation induced mortality, oxidative stress, and immune-suppression. The melatonin pretreated irradiated rats showed less change in body weight as compared to radiation only group. On the other hand, melatonin appeared to have another radioprotective role, suggesting that melatonin may reduce apoptosis through a caspase-3-mediated pathway by blocking caspase-3 activity. PMID:25431791

Growth evolution of AlN films on silicon (111) substrates by pulsed laser deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Haiyan; Wang, Wenliang; Yang, Weijia

2015-05-14

AlN films with various thicknesses have been grown on Si(111) substrates by pulsed laser deposition (PLD). The surface morphology and structural property of the as-grown AlN films have been investigated carefully to comprehensively explore the epitaxial behavior. The ∼2 nm-thick AlN film initially grown on Si substrate exhibits an atomically flat surface with a root-mean-square surface roughness of 0.23 nm. As the thickness increases, AlN grains gradually grow larger, causing a relatively rough surface. The surface morphology of ∼120 nm-thick AlN film indicates that AlN islands coalesce together and eventually form AlN layers. The decreasing growth rate from 240 to 180 nm/h is amore » direct evidence that the growth mode of AlN films grown on Si substrates by PLD changes from the islands growth to the layer growth. The evolution of AlN films throughout the growth is studied deeply, and its corresponding growth mechanism is hence proposed. These results are instructional for the growth of high-quality nitride films on Si substrates by PLD, and of great interest for the fabrication of AlN-based devices.« less

CaMKII prevents spontaneous acrosomal exocytosis in sperm through induction of actin polymerization.

PubMed

Shabtay, Ortal; Breitbart, Haim

2016-07-01

In order to interact with the egg and undergo acrosomal exocytosis or the acrosome reaction (AR), mammalian spermatozoa must undergo a series of biochemical changes in the female reproductive tract, collectively called capacitation. We showed that F-actin is formed during sperm capacitation and fast depolymerization occurs prior to the AR. We hypothesized that F-actin protects the sperm from undergoing spontaneous-AR (sAR) which decreases fertilization rate. We show that activation of the actin-severing protein gelsolin induces a significant increase in sAR. Moreover, inhibition of CaMKII or PLD during sperm capacitation, caused an increase in sAR and inhibition of F-actin formation. Spermine, which leads to PLD activation, was able to reverse the effects of CaMKII inhibition on sAR-increase and F-actin-decrease. Furthermore, the increase in sAR and the decrease in F-actin caused by the inactivation of the PLD-pathway, were reversed by activation of CaMKII using H2O2 or by inhibiting protein phosphatase 1 which enhance the phosphorylation and oxidation states of CaMKII. These results indicate that two distinct pathways lead to F-actin formation in the sperm capacitation process which prevents the occurrence of sAR. Copyright © 2016 Elsevier Inc. All rights reserved.

Virulence gene profiles of Arcobacter species isolated from animals, foods of animal origin, and humans in Andhra Pradesh, India.

PubMed

Sekhar, M Soma; Tumati, S R; Chinnam, B K; Kothapalli, V S; Sharif, N Mohammad

2017-06-01

This study aimed to detect putative virulence genes in Arcobacter species of animal and human origin. A total of 41 Arcobacter isolates (16 Arcobacter butzleri , 13 Arcobacter cryaerophilus , and 12 Arcobacter skirrowii ) isolated from diverse sources such as fecal swabs of livestock (21), raw foods of animal origin (13), and human stool samples (7) were subjected to a set of six uniplex polymerase chain reaction assays targeting Arcobacter putative virulence genes ( ciaB , pldA , tlyA , mviN , cadF , and cj1349 ). All the six virulence genes were detected among all the 16 A. butzleri isolates. Among the 13 A. cryaerophilus isolates, cadF, ciaB , cj1349, mviN , pldA , and tlyA genes were detected in 61.5, 84.6, 76.9, 76.9, 61.5, and 61.5% of isolates, respectively. Among the 12 A. skirrowii isolates, cadF, ciaB , cj1349, mviN , pldA , and tlyA genes were detected in 50.0, 91.6, 83.3, 66.6, 50, and 50% of isolates, respectively. Putative virulence genes were detected in majority of the Arcobacter isolates examined. The results signify the potential of Arcobacter species as an emerging foodborne pathogen.

Oxygen partial pressure influence on the character of InGaZnO thin films grown by PLD

NASA Astrophysics Data System (ADS)

Lu, Yi; Wang, Li

2012-11-01

The amorphous oxide semiconductors (AOSs) are promising for emerging large-area optoelectronic applications because of capability of large-area, uniform deposition at low temperatures such as room temperature (RT). Indium-gallium-zinc oxide (InGaZnO) thin film is a promising amorphous semiconductors material in thin film transistors (TFT) for its excellent electrical properties. In our work, the InGaZnO thin films are fabricated on the SiO2 glass using pulsed laser deposition (PLD) in the oxygen partial pressure altered from 1 to 10 Pa at RT. The targets were prepared by mixing Ga2O3, In2O3, and ZnO powder at a mol ratio of 1: 7: 2 before the solid-state reactions in a tube furnace at the atmospheric pressure. The targets were irradiated by an Nd:YAG laser(355nm). Finally, we have three films of 270nm, 230nm, 190nm thick for 1Pa, 5Pa, 10Pa oxygen partial pressure. The product thin films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), Hall-effect investigation. The comparative study demonstrated the character changes of the structure and electronic transport properties, which is probably occurred as a fact of the different oxygen partial pressure used in the PLD.

Profiling membrane glycerolipids during γ-ray-induced membrane injury.

PubMed

Zheng, Guowei; Li, Weiqi

2017-11-15

γ-rays are high-energy radiation that cause a range of random injuries to plant cells. Most studies on this issue have focused on γ-ray-induced nucleotide damage and the production of reactive oxygen species in cells, so little is known about the glycerolipid metabolism during γ-rays induced membrane injury. Using an ESI-MS/MS-based lipidomic method, we analysed the lipidome changes in wild-type and phospholipase D (PLD)δ- and α1-deficient Arabidopsis after γ-ray treatment. The aim of this study was to investigate the role of PLD-mediated glycerolipid metabolism in γ-ray-induced membrane injury. The ion leakage of Arabidopsis leaves after 2885-Gy γ-ray treatment was less than 10%. High does γ-ray treatment could induce the accumulation of intracellular reactive oxygen species (ROS). Inhibition of PLDα1 caused severe lipid degradation under γ-ray treatment. γ-ray-induced glycerolipid degradation mostly happened in chloroplastidic lipids, rather than extraplastidic ones. The levels of lysophosphatidylcholine (lysoPC) and lysophosphatidylethanolamine (lysoPE) were maintained in the WS ecotypes during γ-ray treatments, while increased significantly in the Col ecotype treated with 1100 Gy. After 210- and 1100-Gy γ-ray treatments, the level of lysophosphatidylglycerol (lysoPG) decreased significantly in the four genotypes of Arabidopsis. γ-ray-induced membrane injury may occur via an indirect mechanism. The degradation of distinct lipids is not synchronous, and that interconversions among lipids can occur. During γ-ray-induced membrane injury, the degradation of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) may be mediated by PLDζ1 or phospholipase A1. The degradation of phosphatidylglycerol was not mediated by PLA, PLDδ or PLDα1, but by phospholipase C or other PLDs. γ-rays can decrease the double-bond index and increase the acyl chain length in membrane lipids, which may make membranes more rigid and further cause injury in membranes.

Lethal and sub-lethal effects on the Asian common toad Duttaphrynus melanostictus from exposure to hexavalent chromium.

PubMed

Fernando, Vindhya A K; Weerasena, Jagathpriya; Lakraj, G Pemantha; Perera, Inoka C; Dangalle, Chandima D; Handunnetti, Shiroma; Premawansa, Sunil; Wijesinghe, Mayuri R

2016-08-01

Chromium discharged in industrial effluents frequently occurs as an environmental pollutant, but the lethal and sub-lethal effects the heavy metal might cause in animals exposed to it have been insufficiently investigated. Selecting the amphibian Duttaphrynus melanostictus, we carried out laboratory tests to investigate the effects of short and long term exposure to hexavalent chromium (Cr(VI)) in both tadpoles and adult toads. The concentrations used were 0.002, 0.02, 0.2, 1.0 and 2.0mg/L, the first three corresponding to field levels. In vitro exposures were also carried out using toad erythrocytes and Cr(VI) concentrations of 0.0015, 0.003, 0.015, 0.03, 0.15mg/L. Mortality, growth retardation, developmental delays and structural aberrations were noted in the metal-treated tadpoles, with increasing incidence corresponding to increase in Cr(VI) level and duration of exposure. Many of the sub-lethal effects were evident with long term exposure to environmentally relevant levels of the toxicant. Changes in selected blood parameters and erythrocyte morphometry were also detected in Cr(VI) exposed toads, indicating anaemic and leucopenic conditions. In the genotoxicity study, DNA damage indicated by comet assay and increased micronuclei frequency, occurred at the low Cr(VI) concentrations tested. The multiple deleterious effects of exposure to chromium signal the need for monitoring and controlling the discharge of chromium to the environment. The dose-dependency and genotoxic effects observed in this widely distributed Asian toad indicates its suitability for monitoring heavy metal pollution in aquatic systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Heat shock modulates the subcellular localization, stability, and activity of HIPK2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Upadhyay, Mamta; Bhadauriya, Pratibha; Ganesh, Subramaniam, E-mail: sganesh@iitk.ac.in

2016-04-15

The homeodomain-interacting protein kinase-2 (HIPK2) is a highly conserved serine/threonine kinase and is involved in transcriptional regulation. HIPK2 is a highly unstable protein, and is kept at a low level under normal physiological conditions. However, exposure of cells to physiological stress – such as hypoxia, oxidative stress, or UV damage – is known to stabilize HIPK2, leading to the HIPK2-dependent activation of p53 and the cell death pathway. Therefore HIPK2 is also known as a stress kinase and as a stress-activated pro-apoptotic factor. We demonstrate here that exposure of cells to heat shock results in the stabilization of HIPK2 andmore » the stabilization is mediated via K63-linked ubiquitination. Intriguingly, a sub-lethal heat shock (42 °C, 1 h) results in the cytoplasmic localization of HIPK2, while a lethal heat shock (45 °C, 1 h) results in its nuclear localization. Cells exposed to the lethal heat shock showed significantly higher levels of the p53 activity than those exposed to the sub-lethal thermal stress, suggesting that both the level and the nuclear localization are essential for the pro-apoptotic activity of HIPK2 and that the lethal heat shock could retain the HIPK2 in the nucleus to promote the cell death. Taken together our study underscores the importance of HIPK2 in stress mediated cell death, and that the HIPK2 is a generic stress kinase that gets activated by diverse set of physiological stressors.« less

Effects of used lubricating oil on two mangroves Aegiceras corniculatum and Avicennia marina.

PubMed

Ye, Yong; Tam, N F Y

2007-01-01

An outdoor experiment was set up to investigate the effects of used lubricating oil (5 L/m2) on Aegiceras corniculatum Blanco. and Avicennia marina (Forsk) Vierh., two salt-excreting mangroves. A. marina was more sensitive to used lubricating oil than A. corniculatum and canopy-oiling resulted in more direct physical damage and stronger lethal effects than base-oiling. When treated with canopy-oiling, half of A. corniculatum plants survived for the whole treatment time (90 d); but, for A. marina, high mortality (83%) resulted from canopy-oiling within 3 weeks and no plants survived for 80 d. Base-oiling had no lethal effects onA. corniculatum plants even at the termination of this experiment, but 83% of A. marina plants died 80 d after treatment. Forty days after canopy-oiling, 93% of A. corniculatum leaves fell and no live leaves remained on A. marina plants. By the end of the experiment, base-oiling treatment resulted in about 45% of A. corniculatum leaves falling, while all A. marina leaves and buds were burned to die. Lubricating oil resulted in physiological damage to A. corniculatum leaves, including decreases in chlorophyll and carotenoid contents, nitrate reductase, peroxidase and superoxide dismutase activities, and increases in malonaldehyde contents. For both species, oil pollution significantly reduced leaf, root, and total biomass, but did not significantly affect stem biomass. Oil pollution resulted in damage to the xylem vessels of fine roots but not to those of mediate roots.

Question of bone marrow stromal fibroblast traffic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maloney, M.A.; Lamela, R.A.; Patt, H.M.

Bone marrow stromal fibroblasts (CFU-F) normally do not exchange bone marrow sites in vivo. Restitution of the CFU-F after radiation damage is primarily recovery by the local fibroblasts from potentially lethal damage. Migration of stromal fibroblasts from shielded sites to an irradiated site makes a minimal contribution, if any, to CFU-F recovery. Determination of the relative contribution of donor stromal cells in bone marrow transplants by karyotyping the proliferating bone marrow stromal cells in vitro may not reflect the relative distribution of fibroblasts in the marrow. If there is residual damage to the host stromal fibroblasts from treatment before transplantation,more » these cells may not be able to proliferate in vitro. Therefore, an occasional transplanted fibroblast may contribute most of the metaphase figures scored for karyotype.« less

PED/PEA-15 inhibits hydrogen peroxide-induced apoptosis in Ins-1E pancreatic beta-cells via PLD-1.

PubMed

Fiory, Francesca; Parrillo, Luca; Raciti, Gregory Alexander; Zatterale, Federica; Nigro, Cecilia; Mirra, Paola; Falco, Roberta; Ulianich, Luca; Di Jeso, Bruno; Formisano, Pietro; Miele, Claudia; Beguinot, Francesco

2014-01-01

The small scaffold protein PED/PEA-15 is involved in several different physiologic and pathologic processes, such as cell proliferation and survival, diabetes and cancer. PED/PEA-15 exerts an anti-apoptotic function due to its ability to interfere with both extrinsic and intrinsic apoptotic pathways in different cell types. Recent evidence shows that mice overexpressing PED/PEA-15 present larger pancreatic islets and increased beta-cells mass. In the present work we investigated PED/PEA-15 role in hydrogen peroxide-induced apoptosis in Ins-1E beta-cells. In pancreatic islets isolated from Tg(PED/PEA-15) mice hydrogen peroxide-induced DNA fragmentation was lower compared to WT islets. TUNEL analysis showed that PED/PEA-15 overexpression increases the viability of Ins-1E beta-cells and enhances their resistance to apoptosis induced by hydrogen peroxide exposure. The activity of caspase-3 and the cleavage of PARP-1 were markedly reduced in Ins-1E cells overexpressing PED/PEA-15 (Ins-1E(PED/PEA-15)). In parallel, we observed a decrease of the mRNA levels of pro-apoptotic genes Bcl-xS and Bad. In contrast, the expression of the anti-apoptotic gene Bcl-xL was enhanced. Accordingly, DNA fragmentation was higher in control cells compared to Ins-1E(PED/PEA-15) cells. Interestingly, the preincubation with propranolol, an inhibitor of the pathway of PLD-1, a known interactor of PED/PEA-15, responsible for its deleterious effects on glucose tolerance, abolishes the antiapoptotic effects of PED/PEA-15 overexpression in Ins-1E beta-cells. The same results have been obtained by inhibiting PED/PEA-15 interaction with PLD-1 in Ins-1E(PED/PEA-15). These results show that PED/PEA-15 overexpression is sufficient to block hydrogen peroxide-induced apoptosis in Ins-1E cells through a PLD-1 mediated mechanism.

Arachidonic acid-containing phosphatidylcholine characterized by consolidated plasma and liver lipidomics as an early onset marker for tamoxifen-induced hepatic phospholipidosis.

PubMed

Saito, Kosuke; Goda, Keisuke; Kobayashi, Akio; Yamada, Naohito; Maekawa, Kyoko; Saito, Yoshiro; Sugai, Shoichiro

2017-08-01

Lipid profiling has emerged as an effective approach to not only screen disease and drug toxicity biomarkers but also understand their underlying mechanisms of action. Tamoxifen, a widely used antiestrogenic agent for adjuvant therapy against estrogen-positive breast cancer, possesses side effects such as hepatic steatosis and phospholipidosis (PLD). In the present study, we administered tamoxifen to Sprague-Dawley rats and used lipidomics to reveal tamoxifen-induced alteration of the hepatic lipid profile and its association with the plasma lipid profile. Treatment with tamoxifen for 28 days caused hepatic PLD in rats. We compared the plasma and liver lipid profiles in treated vs. untreated rats using a multivariate analysis to determine differences between the two groups. In total, 25 plasma and 45 liver lipids were identified and altered in the tamoxifen-treated group. Of these lipids, arachidonic acid (AA)-containing phosphatidylcholines (PCs), such as PC (17:0/20:4) and PC (18:1/20:4), were commonly reduced in both plasma and liver. Conversely, tamoxifen increased other phosphoglycerolipids in the liver, such as phosphatidylethanolamine (18:1/18:1) and phosphatidylinositol (18:0/18:2). We also examined alteration of AA-containing PCs and some phosphoglycerolipids in the pre-PLD stage and found that these lipid alterations were initiated before pathological alteration in the liver. In addition, changes in plasma and liver levels of AA-containing PCs were linearly associated. Moreover, levels of free AA and mRNA levels of AA-synthesizing enzymes, such as fatty acid desaturase 1 and 2, were decreased by tamoxifen treatment. Therefore, our study demonstrated that AA-containing PCs might have potential utility as novel and predictive biomarkers for tamoxifen-induced PLD. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Study of the Effects of Ultrasonic Waves on the Reproductive Integrity of Mammalian Cells Cultured in Vitro

NASA Technical Reports Server (NTRS)

Martins, B. I.

1971-01-01

The effects of monochromatic ultrasonic waves of 0.1, 0.5, 1.0, 2.0 and, 3.3 MHz frequency on the colony-forming ability of mammalian cells (M3-1,V79, Chang's and T-1) cultured in vitro have been studied to determine the nature of the action of ultrasonic energy on biological systems at the cellular level. The combined effect of ultrasound and X-rays has also been studied. It is concluded: (1) Ultrasonic irradiation causes both lethal and sublethal damage. (2) There is a threshold dose rate for lethal effects. (3) The effectiveness of ultrasonic waves in causing cell death probably depends on the frequency and the amplitude of the waves for a given cell line, indicating a possible resonance phenomenon.

HIPK2 restricts SIRT1 activity upon severe DNA damage by a phosphorylation-controlled mechanism

PubMed Central

Conrad, E; Polonio-Vallon, T; Meister, M; Matt, S; Bitomsky, N; Herbel, C; Liebl, M; Greiner, V; Kriznik, B; Schumacher, S; Krieghoff-Henning, E; Hofmann, T G

2016-01-01

Upon severe DNA damage a cellular signalling network initiates a cell death response through activating tumour suppressor p53 in association with promyelocytic leukaemia (PML) nuclear bodies. The deacetylase Sirtuin 1 (SIRT1) suppresses cell death after DNA damage by antagonizing p53 acetylation. To facilitate efficient p53 acetylation, SIRT1 function needs to be restricted. How SIRT1 activity is regulated under these conditions remains largely unclear. Here we provide evidence that SIRT1 activity is limited upon severe DNA damage through phosphorylation by the DNA damage-responsive kinase HIPK2. We found that DNA damage provokes interaction of SIRT1 and HIPK2, which phosphorylates SIRT1 at Serine 682 upon lethal damage. Furthermore, upon DNA damage SIRT1 and HIPK2 colocalize at PML nuclear bodies, and PML depletion abrogates DNA damage-induced SIRT1 Ser682 phosphorylation. We show that Ser682 phosphorylation inhibits SIRT1 activity and impacts on p53 acetylation, apoptotic p53 target gene expression and cell death. Mechanistically, we found that DNA damage-induced SIRT1 Ser682 phosphorylation provokes disruption of the complex between SIRT1 and its activator AROS. Our findings indicate that phosphorylation-dependent restriction of SIRT1 activity by HIPK2 shapes the p53 response. PMID:26113041

Current status and future prospects of Japanese national project on coated conductor development and its applications

NASA Astrophysics Data System (ADS)

Shiohara, Y.; Yoshizumi, M.; Izumi, T.; Yamada, Y.

2008-09-01

Four years of the current five-year national project since 2003 for development of coated conductors using Y-system superconductors have passed and lots of remarkable results have been achieved. In this paper, the current status and the future prospect of this project are reviewed. The current national project comprises several groups of national laboratories, universities and private companies. The group of high performance tape development, consisting of Fujikura and SRL-NCCC, has worked on the tape by PLD-REBCO superconducting tapes on the PLD-CeO 2/IBAD-GZO buffered substrates. The high product of Ic and L equal to 112,166 A m was achieved in the 368 m-304.8 A GdBCO tape whose Ic value is mostly above 350 A/cm-w. The performance under the magnetic fields was also improved up to 42 A at 3 T in a GdBCO short film with doping of ZrO 2. About 61 m long GdBCO tape with ZrO 2 doping showed a high Ic value of 220 A at self field and 30 A at 3 T. On the other hand, the other group focusing on the low production cost has worked on processes of TFA-MOD and MOCVD, etc. The extremely high Ic value of 735 A/cm-w was attained in the TFA-MOD films on PLD-CeO 2/IBAD-GZO/Hastelloy C276 substrate by means of using the effect of Ba-poor nominal composition. In the efforts for long tape production, 200 m long tapes with high Ic values of 200 A/cm-w and 205 A/cm-w were obtained by MOD-YBCO/PLD-CeO 2/IBAD-GZO/Hastelloy C276 and PLD-HoBCO on buffered NiW substrate, respectively. The Ic × L value of the MOD-derived tape was 40,000 A m, which is the highest value in the world by the MOD process. Based on the above achievements on the coated conductor process development, two new additional goals were set in the project. One is the development for the extremely low cost tape and another is the development of the basic technologies for making the electric power devices including cables, transformers, motors, current-limiters and cryocoolers. Some of the new themes already revealed the marvellous results such as 15 kW motor, low AC loss coils, low AC loss cables, etc.

A geometric model of mortality and crop protection for insects feeding on discrete toxicant deposits.

PubMed

Ebert, Timothy; Derksen, Richard

2004-04-01

Current theory governing the biological effectiveness of toxicants stresses the dose-response relationship and focuses on uniform toxicant distributions in the insect's environment. However, toxicants are seldom uniformly dispersed under field conditions. Toxicant distribution affects bioavailability, but the mechanics of such interactions is not well documented. We present a geometric model of the interactions between insects and heterogeneously distributed toxicants. From the model, we conclude the following: 1) There is an optimal droplet size, and droplets both smaller and larger than this optimum will decrease efficacy. 2) There is an ideal droplet distribution. Droplets should be spaced based on two criteria: calculate the allowable damage, double this quantity, and one lethal deposit should be placed in this area; and define the quantity of leaf the larva could eat before the toxicant decays below the lethal level and place one lethal deposit within this area. 3) Distributions of toxicant where deposits are sublethal will often be ineffective, but the application is wasteful if deposits contain more than a lethal dose. 4) Insect behavior both as individuals and collectively influences the level of crop production provided by an application. This conclusion has implications for both crop protection and natural plant-insect interactions. The effective utilization of new more environmentally sensitive toxicants may depend on how well we understand how heterogeneous toxicant distributions interact with insect behavior to determine the biological outcome.

OH radicals from the indirect actions of X-rays induce cell lethality and mediate the majority of the oxygen enhancement effect.

PubMed

Hirayama, Ryoichi; Ito, Atsushi; Noguchi, Miho; Matsumoto, Yoshitaka; Uzawa, Akiko; Kobashi, Gen; Okayasu, Ryuichi; Furusawa, Yoshiya

2013-11-01

We examined OH radical-mediated indirect actions from X irradiation on cell killing in wild-type Chinese hamster ovary cell lines (CHO and AA8) under oxic and hypoxic conditions, and compared the contribution of direct and indirect actions under both conditions. The contribution of indirect action on cell killing can be estimated from the maximum degree of protection by dimethylsulfoxide, which suppresses indirect action by quenching OH radicals without affecting the direct action of X rays on cell killing. The contributions of indirect action on cell killing of CHO cells were 76% and 50% under oxic and hypoxic conditions, respectively, and those for AA8 cells were 85% and 47%, respectively. Therefore, the indirect action on cell killing was enhanced by oxygen during X irradiation in both cell lines tested. Oxygen enhancement ratios (OERs) at the 10% survival level (D10 or LD90) for CHO and AA8 cells were 2.68 ± 0.15 and 2.76 ± 0.08, respectively. OERs were evaluated separately for indirect and direct actions, which gave the values of 3.75 and 2.01 for CHO, and 4.11 and 1.32 for AA8 cells, respectively. Thus the generally accepted OER value of ∼3 is best understood as the average of the OER values for both indirect and direct actions. These results imply that both indirect and direct actions on cell killing require oxygen for the majority of lethal DNA damage, however, oxygen plays a larger role in indirect than for direct effects. Conversely, the lethal damage induced by the direct action of X rays are less affected by oxygen concentration.

CLEC5A Regulates Japanese Encephalitis Virus-Induced Neuroinflammation and Lethality

PubMed Central

Chen, Szu-Ting; Liu, Ren-Shyan; Wu, Ming-Fang; Lin, Yi-Ling; Chen, Se-Yi; Tan, David Tat-Wei; Chou, Teh-Ying; Tsai, I-Shuen; Li, Lei; Hsieh, Shie-Liang

2012-01-01

CLEC5A/MDL-1, a member of the myeloid C-type lectin family expressed on macrophages and neutrophils, is critical for dengue virus (DV)-induced hemorrhagic fever and shock syndrome in Stat1 −/− mice and ConA-treated wild type mice. However, whether CLEC5A is involved in the pathogenesis of viral encephalitis has not yet been investigated. To investigate the role of CLEC5A to regulate JEV-induced neuroinflammation, antagonistic anti-CLEC5A mAb and CLEC5A-deficient mice were generated. We find that Japanese encephalitis virus (JEV) directly interacts with CLEC5A and induces DAP12 phosphorylation in macrophages. In addition, JEV activates macrophages to secrete proinflammatory cytokines and chemokines, which are dramatically reduced in JEV-infected Clec5a−/− macrophages. Although blockade of CLEC5A cannot inhibit JEV infection of neurons and astrocytes, anti-CLEC5A mAb inhibits JEV-induced proinflammatory cytokine release from microglia and prevents bystander damage to neuronal cells. Moreover, JEV causes blood-brain barrier (BBB) disintegrity and lethality in STAT1-deficient (Stat1 −/−) mice, whereas peripheral administration of anti-CLEC5A mAb reduces infiltration of virus-harboring leukocytes into the central nervous system (CNS), restores BBB integrity, attenuates neuroinflammation, and protects mice from JEV-induced lethality. Moreover, all surviving mice develop protective humoral and cellular immunity against JEV infection. These observations demonstrate the critical role of CLEC5A in the pathogenesis of Japanese encephalitis, and identify CLEC5A as a target for the development of new treatments to reduce virus-induced brain damage. PMID:22536153

Monoketone analogs of curcumin, a new class of Fanconi anemia pathway inhibitors.

PubMed

Landais, Igor; Hiddingh, Sanne; McCarroll, Matthew; Yang, Chao; Sun, Aiming; Turker, Mitchell S; Snyder, James P; Hoatlin, Maureen E

2009-12-31

The Fanconi anemia (FA) pathway is a multigene DNA damage response network implicated in the repair of DNA lesions that arise during replication or after exogenous DNA damage. The FA pathway displays synthetic lethal relationship with certain DNA repair genes such as ATM (Ataxia Telangectasia Mutated) that are frequently mutated in tumors. Thus, inhibition of FANCD2 monoubiquitylation (FANCD2-Ub), a key step in the FA pathway, might target tumor cells defective in ATM through synthetic lethal interaction. Curcumin was previously identified as a weak inhibitor of FANCD2-Ub. The aim of this study is to identify derivatives of curcumin with better activity and specificity. Using a replication-free assay in Xenopus extracts, we screened monoketone analogs of curcumin for inhibition of FANCD2-Ub and identified analog EF24 as a strong inhibitor. Mechanistic studies suggest that EF24 targets the FA pathway through inhibition of the NF-kB pathway kinase IKK. In HeLa cells, nanomolar concentrations of EF24 inhibited hydroxyurea (HU)-induced FANCD2-Ub and foci in a cell-cycle independent manner. Survival assays revealed that EF24 specifically sensitizes FA-competent cells to the DNA crosslinking agent mitomycin C (MMC). In addition, in contrast with curcumin, ATM-deficient cells are twofold more sensitive to EF24 than matched wild-type cells, consistent with a synthetic lethal effect between FA pathway inhibition and ATM deficiency. An independent screen identified 4H-TTD, a compound structurally related to EF24 that displays similar activity in egg extracts and in cells. These results suggest that monoketone analogs of curcumin are potent inhibitors of the FA pathway and constitute a promising new class of targeted anticancer compounds.

Monoketone analogs of curcumin, a new class of Fanconi anemia pathway inhibitors

PubMed Central

2009-01-01

Background The Fanconi anemia (FA) pathway is a multigene DNA damage response network implicated in the repair of DNA lesions that arise during replication or after exogenous DNA damage. The FA pathway displays synthetic lethal relationship with certain DNA repair genes such as ATM (Ataxia Telangectasia Mutated) that are frequently mutated in tumors. Thus, inhibition of FANCD2 monoubiquitylation (FANCD2-Ub), a key step in the FA pathway, might target tumor cells defective in ATM through synthetic lethal interaction. Curcumin was previously identified as a weak inhibitor of FANCD2-Ub. The aim of this study is to identify derivatives of curcumin with better activity and specificity. Results Using a replication-free assay in Xenopus extracts, we screened monoketone analogs of curcumin for inhibition of FANCD2-Ub and identified analog EF24 as a strong inhibitor. Mechanistic studies suggest that EF24 targets the FA pathway through inhibition of the NF-kB pathway kinase IKK. In HeLa cells, nanomolar concentrations of EF24 inhibited hydroxyurea (HU)-induced FANCD2-Ub and foci in a cell-cycle independent manner. Survival assays revealed that EF24 specifically sensitizes FA-competent cells to the DNA crosslinking agent mitomycin C (MMC). In addition, in contrast with curcumin, ATM-deficient cells are twofold more sensitive to EF24 than matched wild-type cells, consistent with a synthetic lethal effect between FA pathway inhibition and ATM deficiency. An independent screen identified 4H-TTD, a compound structurally related to EF24 that displays similar activity in egg extracts and in cells. Conclusions These results suggest that monoketone analogs of curcumin are potent inhibitors of the FA pathway and constitute a promising new class of targeted anticancer compounds. PMID:20043851

Dynamic in vivo imaging of small animal brain using pulsed laser diode-based photoacoustic tomography system

NASA Astrophysics Data System (ADS)

Upputuri, Paul Kumar; Pramanik, Manojit

2017-09-01

We demonstrate dynamic in vivo imaging using a low-cost portable pulsed laser diode (PLD)-based photoacoustic tomography system. The system takes advantage of an 803-nm PLD having high-repetition rate ˜7000 Hz combined with a fast-scanning single-element ultrasound transducer leading to a 5 s cross-sectional imaging. Cortical vasculature is imaged in scan time of 5 s with high signal-to-noise ratio ˜48. To examine the ability for dynamic imaging, we monitored the fast uptake and clearance process of indocyanine green in the rat brain. The system will find applications to study neurofunctional activities, characterization of pharmacokinetic, and biodistribution profiles in the development process of drugs or imaging agents.

Pulsed laser deposition of functionalized Mg-Al layered double hydroxide thin films

NASA Astrophysics Data System (ADS)

Vlad, A.; Birjega, R.; Tirca, I.; Matei, A.; Mardare, C. C.; Hassel, A. W.; Nedelcea, A.; Dinescu, M.; Zavoianu, R.

2018-02-01

In this paper, magnesium-aluminium layered double hydroxide (LDH) has been functionalized with sodium dodecyl sulfate (DS) and deposited as thin film by pulsed laser deposition (PLD). Mg, Al-LDH powders were prepared by co-precipitation and used as reference material. Intercalation of DS as an anionic surfactant into the LDHs host layers has been prepared in two ways: co-precipitation (P) and reconstruction (R). DS intercalation occurred in LDH powder via both preparation methods. The films deposited via PLD, in particular at 532 and 1064 nm, preserve the organic intercalated layered structure of the targets prepared from these powders. The results reveal the ability of proposed deposition technique to produce functional composite organo-modified LDHs thin films.

Pulsed laser deposition of air-sensitive hydride epitaxial thin films: LiH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oguchi, Hiroyuki, E-mail: oguchi@nanosys.mech.tohoku.ac.jp; Micro System Integration Center; Isobe, Shigehito

2015-09-01

We report on the epitaxial thin film growth of an air-sensitive hydride, lithium hydride (LiH), using pulsed laser deposition (PLD). We first synthesized a dense LiH target, which is key for PLD growth of high-quality hydride films. Then, we obtained epitaxial thin films of [100]-oriented LiH on a MgO(100) substrate at 250 °C under a hydrogen pressure of 1.3 × 10{sup −2} Pa. Atomic force microscopy revealed that the film demonstrates a Stranski-Krastanov growth mode and that the film with a thickness of ∼10 nm has a good surface flatness, with root-mean-square roughness R{sub RMS} of ∼0.4 nm.

Novel Strategies to Enhance Vaccine Immunity against Coccidioidomycosis

DTIC Science & Technology

2013-12-19

Mexico and Central and South America [1]. Coccidioides is a dimorphic ascomycetous fungus with distinct saprobic and parasitic phases and is classified in...lethal spore inoculum. However, sterile immunity was not achieved and pulmonary tissue damage associated with a persistent host inflammatory response...observation will translate to humans. A recent vector-based vaccine against tuberculosis intended to protect by eliciting strong CMI failed in humans despite

A single major QTL controls expression of larval Cry1F resistance trait in Ostrinia nubilalis (Lepidoptera: Crambidae) and is independent of midgut receptor genes

USDA-ARS?s Scientific Manuscript database

European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), is an introduced crop pest in North America that causes major damage to corn, and reduces yield of food, feed, and biofuel materials. Transgenic hybrid corn expressing the Bacillus thuringiensis (Bt) toxin Cry1F is highly lethal to O...

Armored Family of Vehicles (AFV). Phase 1 Report. Book 3. Volumes 5 thru 8

DTIC Science & Technology

1987-08-31

tactical mobility /agility, tactical and strategic deployability, rapid repair/replacement of damaged or destroyed equipment, lethality, reduced...Mover (CEM). (15) Combat Mobility Vehicle (CMV). (16) Combat Gap Crosser (CGC). (17) Combat Excavator (CEX). (18) Mine Dispensing Vehicle (MDV). (19...economic decision analysis (IAW AR 700-XX, AR 700-127 and AR 700-17) and consideration of mobilization requirements. 7. Transportability

Aag DNA Glycosylase Promotes Alkylation-Induced Tissue Damage Mediated by Parp1

PubMed Central

Calvo, Jennifer A.; Moroski-Erkul, Catherine A.; Lake, Annabelle; Eichinger, Lindsey W.; Shah, Dharini; Jhun, Iny; Limsirichai, Prajit; Bronson, Roderick T.; Christiani, David C.; Meira, Lisiane B.; Samson, Leona D.

2013-01-01

Alkylating agents comprise a major class of front-line cancer chemotherapeutic compounds, and while these agents effectively kill tumor cells, they also damage healthy tissues. Although base excision repair (BER) is essential in repairing DNA alkylation damage, under certain conditions, initiation of BER can be detrimental. Here we illustrate that the alkyladenine DNA glycosylase (AAG) mediates alkylation-induced tissue damage and whole-animal lethality following exposure to alkylating agents. Aag-dependent tissue damage, as observed in cerebellar granule cells, splenocytes, thymocytes, bone marrow cells, pancreatic β-cells, and retinal photoreceptor cells, was detected in wild-type mice, exacerbated in Aag transgenic mice, and completely suppressed in Aag −/− mice. Additional genetic experiments dissected the effects of modulating both BER and Parp1 on alkylation sensitivity in mice and determined that Aag acts upstream of Parp1 in alkylation-induced tissue damage; in fact, cytotoxicity in WT and Aag transgenic mice was abrogated in the absence of Parp1. These results provide in vivo evidence that Aag-initiated BER may play a critical role in determining the side-effects of alkylating agent chemotherapies and that Parp1 plays a crucial role in Aag-mediated tissue damage. PMID:23593019

Imaging and radiation effects of gold nanoparticles in tumour cells

PubMed Central

McQuaid, Harold N.; Muir, Mark F.; Taggart, Laura E.; McMahon, Stephen J.; Coulter, Jonathan A.; Hyland, Wendy B.; Jain, Suneil; Butterworth, Karl T.; Schettino, Giuseppe; Prise, Kevin M.; Hirst, David G.; Botchway, Stanley W.; Currell, Fred J.

2016-01-01

Gold nanoparticle radiosensitization represents a novel technique in enhancement of ionising radiation dose and its effect on biological systems. Variation between theoretical predictions and experimental measurement is significant enough that the mechanism leading to an increase in cell killing and DNA damage is still not clear. We present the first experimental results that take into account both the measured biodistribution of gold nanoparticles at the cellular level and the range of the product electrons responsible for energy deposition. Combining synchrotron-generated monoenergetic X-rays, intracellular gold particle imaging and DNA damage assays, has enabled a DNA damage model to be generated that includes the production of intermediate electrons. We can therefore show for the first time good agreement between the prediction of biological outcomes from both the Local Effect Model and a DNA damage model with experimentally observed cell killing and DNA damage induction via the combination of X-rays and GNPs. However, the requirement of two distinct models as indicated by this mechanistic study, one for short-term DNA damage and another for cell survival, indicates that, at least for nanoparticle enhancement, it is not safe to equate the lethal lesions invoked in the local effect model with DNA damage events. PMID:26787230

Temperature dependency of the repair of sublethal damage in cultured fish cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitani, H.; Egami, N.

1984-01-01

Established culture fish cells, CAF-MMMI, derived form the goldfish, Carassium auratus, were able to grow and form colonies over a temperature range from 20 to 33/sup 0/ C. While the growth rate of these cells was dependent on incubation temperature, colony formation had no effect on cell survival after ..gamma.. irradiation at high dose rates. The lethal effect of ..gamma.. rays was decreased at low dose rates at 20-33/sup 0/ C, but not at 6/sup 0/ C. Similarly, split-dose experiments showed that recovery from sublethal damage occurred at the higher temperatures, but not at 6/sup 0/ C. These data aremore » consistent with the in vivo data on the effect of temperature on the radiosensitivity and repair of sublethal damage reported previously for live fish.« less

Alveolar Macrophages Prevent Lethal Influenza Pneumonia By Inhibiting Infection Of Type-1 Alveolar Epithelial Cells

PubMed Central

Cardani, Amber; Boulton, Adam; Kim, Taeg S.; Braciale, Thomas J.

2017-01-01

The Influenza A virus (IAV) is a major human pathogen that produces significant morbidity and mortality. To explore the contribution of alveolar macrophages (AlvMΦs) in regulating the severity of IAV infection we employed a murine model in which the Core Binding Factor Beta gene is conditionally disrupted in myeloid cells. These mice exhibit a selective deficiency in AlvMΦs. Following IAV infection these AlvMΦ deficient mice developed severe diffuse alveolar damage, lethal respiratory compromise, and consequent lethality. Lethal injury in these mice resulted from increased infection of their Type-1 Alveolar Epithelial Cells (T1AECs) and the subsequent elimination of the infected T1AECs by the adaptive immune T cell response. Further analysis indicated AlvMΦ-mediated suppression of the cysteinyl leukotriene (cysLT) pathway genes in T1AECs in vivo and in vitro. Inhibition of the cysLT pathway enzymes in a T1AECs cell line reduced the susceptibility of T1AECs to IAV infection, suggesting that AlvMΦ-mediated suppression of this pathway contributes to the resistance of T1AECs to IAV infection. Furthermore, inhibition of the cysLT pathway enzymes, as well as blockade of the cysteinyl leukotriene receptors in the AlvMΦ deficient mice reduced the susceptibility of their T1AECs to IAV infection and protected these mice from lethal infection. These results suggest that AlvMΦs may utilize a previously unappreciated mechanism to protect T1AECs against IAV infection, and thereby reduce the severity of infection. The findings further suggest that the cysLT pathway and the receptors for cysLT metabolites represent potential therapeutic targets in severe IAV infection. PMID:28085958

Rescue of bilirubin-induced neonatal lethality in a mouse model of Crigler-Najjar syndrome type I by AAV9-mediated gene transfer

PubMed Central

Bortolussi, Giulia; Zentilin, Lorena; Baj, Gabriele; Giraudi, Pablo; Bellarosa, Cristina; Giacca, Mauro; Tiribelli, Claudio; Muro, Andrés F.

2012-01-01

Crigler-Najjar type I (CNI) syndrome is a recessively inherited disorder characterized by severe unconjugated hyperbilirubinemia caused by uridine diphosphoglucuronosyltransferase 1A1 (UGT1A1) deficiency. The disease is lethal due to bilirubin-induced neurological damage unless phototherapy is applied from birth. However, treatment becomes less effective during growth, and liver transplantation is required. To investigate the pathophysiology of the disease and therapeutic approaches in mice, we generated a mouse model by introducing a premature stop codon in the UGT1a1 gene, which results in an inactive enzyme. Homozygous mutant mice developed severe jaundice soon after birth and died within 11 d, showing significant cerebellar alterations. To rescue neonatal lethality, newborns were injected with a single dose of adeno-associated viral vector 9 (AAV9) expressing the human UGT1A1. Gene therapy treatment completely rescued all AAV-treated mutant mice, accompanied by lower plasma bilirubin levels and normal brain histology and motor coordination. Our mouse model of CNI reproduces genetic and phenotypic features of the human disease. We have shown, for the first time, the full recovery of the lethal effects of neonatal hyperbilirubinemia. We believe that, besides gene-addition-based therapies, our mice could represent a very useful model to develop and test novel technologies based on gene correction by homologous recombination.—Bortolussi, G., Zentilin, L., Baj, G., Giraudi, P., Bellarosa, C., Giacca, M., Tiribelli, C., Muro, A. F. Rescue of bilirubin-induced neonatal lethality in a mouse model of Crigler-Najjar syndrome type I by AAV9-mediated gene transfer. PMID:22094718

Efficacy of Favipiravir Alone and in Combination With Ribavirin in a Lethal, Immunocompetent Mouse Model of Lassa Fever.

PubMed

Oestereich, Lisa; Rieger, Toni; Lüdtke, Anja; Ruibal, Paula; Wurr, Stephanie; Pallasch, Elisa; Bockholt, Sabrina; Krasemann, Susanne; Muñoz-Fontela, César; Günther, Stephan

2016-03-15

We studied the therapeutic potential of favipiravir (T-705) for Lassa fever, both alone and in combination with ribavirin. Favipiravir suppressed Lassa virus replication in cell culture by 5 log10 units. In a novel lethal mouse model, it lowered the viremia level and the virus load in organs and normalized levels of cell-damage markers. Treatment with 300 mg/kg per day, commenced 4 days after infection, when the viremia level had reached 4 log10 virus particles/mL, rescued 100% of Lassa virus-infected mice. We found a synergistic interaction between favipiravir and ribavirin in vitro and an increased survival rate and extended survival time when combining suboptimal doses in vivo. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America.

Central nervous system damage due to acute paraquat poisoning: an experimental study with rat model.

PubMed

Wu, Bailin; Song, Bo; Yang, Haiqing; Huang, Boyuan; Chi, Bo; Guo, Yansu; Liu, Huaijun

2013-03-01

Paraquat (PQ) is a common herbicide and PQ poisoning is a major medical problem in Asia. However, few studies have focused on the acute neurotoxic changes caused by PQ. Here we report the acute neurotoxicological findings of rats treated with lethal dose of PQ. In substantia nigra (SN) and striatum we found obvious microglia (labeled by Iba-1) activation within one week. In SN and hippocampus, we detected increased oxidative stress in the neurons based on NeuN/8-OHdG immunofluorescence double labeling and laser cofocal microscopy. Moreover, we provided ultrastructural evidences of astrocyte edema and neurons apoptosis in rat brain by electron microscopy. Further studies will be needed with non-lethal dose of PQ to confirm these results and demonstrate the direct CNS toxicity of PQ. Copyright © 2012 Elsevier Inc. All rights reserved.

Endothelial cell cytotoxicity of cotton bracts tannin and aqueous cotton bracts extract

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, C.M.; Hanson, M.N.; Rohrbach, M.S.

1986-04-01

Using an in vitro cytotoxicity assay based on the release of /sup 51/Cr from cultured porcine thoracic aortic and pulmonary arterial endothelial cells, we have demonstrated that cotton bracts tannin is a potent endothelial cell cytotoxin. It produces dose-dependent lethal injury to both types of endothelial cells with the aortic cells, being somewhat more sensitive to tannin-mediated injury than the pulmonary arterial cells. Cytotoxic injury to the cells was biphasic. During the first 3 hr of exposure to tannin, no lethal injury was detected. However, during this period, profound changes in morphology were observed suggesting sublethal injury to the cellsmore » preceded the ultimate toxic damage. Comparison of the cytotoxicity dose curves for aqueous bracts extracts with those for tannin demonstrated that tannin was major cytotoxin present in bracts.« less

GLUT4-containing vesicles are released from membranes by phospholipase D cleavage of a GPI anchor.

PubMed

Kristiansen, Søren; Richter, Erik A

2002-08-01

We have previously developed a cell-free assay from rat skeletal muscle that displayed in vitro glucose transporter 4 (GLUT4) transfer from large to small membrane structures by the addition of a cytosolic protein fraction. By combining protein fractionation and the in vitro GLUT4 transfer assay, we have purified a glycosylphosphatidylinositol (GPI) phospholipase D (PLD) that induces transfer of GLUT4 from small to large membranes. The in vitro GLUT4 transfer was activated and inhibited by suramin and 1,10-phenanthroline (an activator and an inhibitor of GPI-PLD activity, respectively). Furthermore, upon purification of the GLUT4 transporter protein, the protein displayed an elution profile in which the molecular mass was related to the charge, suggesting the presence or absence of phosphate. Second, by photoaffinity labeling of the purified GLUT4 with 3-(trifluoromethyl)-3-(m-[(125)I]iodopenyl)diazirine, both labeled phosphatidylethanolamine and fatty acids (constituents of a GPI link) were recovered. Third, by using phase transition of Triton X-114, the purified GLUT4 was found to be partly detergent resistant, which is a known characteristic of GPI-linked proteins. Fourth, the purified GLUT4 protein was recognized by an antibody raised specifically against GPI links. In conclusion, GLUT4-containing vesicles may be released from a membrane compartment by action of a GPI-PLD.

Convection-enhanced delivery of a topoisomerase I inhibitor (nanoliposomal topotecan) and a topoisomerase II inhibitor (pegylated liposomal doxorubicin) in intracranial brain tumor xenografts1

PubMed Central

Yamashita, Yoji; Krauze, Michal T.; Kawaguchi, Tomohiro; Noble, Charles O.; Drummond, Daryl C.; Park, John W.; Bankiewicz, Krystof S.

2007-01-01

Despite multimodal treatment options, the response and survival rates for patients with malignant gliomas remain dismal. Clinical trials with convection-enhanced delivery (CED) have recently opened a new window in neuro-oncology to the direct delivery of chemotherapeutics to the CNS, circumventing the blood-brain barrier and reducing systemic side effects. Our previous CED studies with liposomal chemotherapeutics have shown promising antitumor activity in rodent brain tumor models. In this study, we evaluated a combination of nanoliposomal topotecan (nLs-TPT) and pegylated liposomal doxorubicin (PLD) to enhance efficacy in our brain tumor models, and to establish a CED treatment capable of improving survival from malignant brain tumors. Both liposomal drugs decreased key enzymes involved in tumor cell replication in vitro. Synergistic effects of nLs-TPT and PLD on U87MG cell death were found. The combination displayed excellent efficacy in a CED-based survival study 10 days after tumor cell implantation. Animals in the control group and those in single-agent groups had a median survival of less than 30 days, whereas the combination group experienced a median survival of more than 90 days. We conclude that CED of two liposomal chemotherapeutics (nLs-TPT and PLD) may be an effective treatment option for malignant gliomas. PMID:17018695

Phosphatidic Acid Produced by Phospholipase D Promotes RNA Replication of a Plant RNA Virus

PubMed Central

Hyodo, Kiwamu; Taniguchi, Takako; Manabe, Yuki; Kaido, Masanori; Mise, Kazuyuki; Sugawara, Tatsuya; Taniguchi, Hisaaki; Okuno, Tetsuro

2015-01-01

Eukaryotic positive-strand RNA [(+)RNA] viruses are intracellular obligate parasites replicate using the membrane-bound replicase complexes that contain multiple viral and host components. To replicate, (+)RNA viruses exploit host resources and modify host metabolism and membrane organization. Phospholipase D (PLD) is a phosphatidylcholine- and phosphatidylethanolamine-hydrolyzing enzyme that catalyzes the production of phosphatidic acid (PA), a lipid second messenger that modulates diverse intracellular signaling in various organisms. PA is normally present in small amounts (less than 1% of total phospholipids), but rapidly and transiently accumulates in lipid bilayers in response to different environmental cues such as biotic and abiotic stresses in plants. However, the precise functions of PLD and PA remain unknown. Here, we report the roles of PLD and PA in genomic RNA replication of a plant (+)RNA virus, Red clover necrotic mosaic virus (RCNMV). We found that RCNMV RNA replication complexes formed in Nicotiana benthamiana contained PLDα and PLDβ. Gene-silencing and pharmacological inhibition approaches showed that PLDs and PLDs-derived PA are required for viral RNA replication. Consistent with this, exogenous application of PA enhanced viral RNA replication in plant cells and plant-derived cell-free extracts. We also found that a viral auxiliary replication protein bound to PA in vitro, and that the amount of PA increased in RCNMV-infected plant leaves. Together, our findings suggest that RCNMV hijacks host PA-producing enzymes to replicate. PMID:26020241

Geologic history of the polar regions of Mars based on Mars Global surveyor data. II. Amazonian period

USGS Publications Warehouse

Kolb, E.J.; Tanaka, K.L.

2001-01-01

Based on Mars Orbiter Laser Altimeter (MOLA) and Mars Orbiter Camera (MOC) observations of Amazonian polar layered deposits' (PLD) morphology, composition, and thickness, we conclude that the PLDs are composed of porous unconsolidated layers that have not experienced significant basal melting or other glacial-type processes. Morphologic features and associations within the PLD chasmata, including preserved craters and sinuous ridges, indicate that the dominant process of chasmata formation is wind scouring. Our detailed analysis of south polar spiral-trough topography, in conjunction with the identification of similar layered stratigraphy within north polar spiral troughs, suggests that trough migration due to preferential ablation of Sun-facing slopes cannot be demonstrated. Within the layered sequences, we have not identified widespread unconformities, discontinuities, or pinch-outs that would indicate an accublation origin of the PLDs. We therefore postulate that the well-defined PLDs at both poles eventually reached and maintained their present form following deposition without extensive deformation or redeposition. Large, cuspate ridges in the Ultimi lobe of Planum Australe appear to be layered and may be unusual erosional remnants of a once thicker PLD in this area. Beneath the north polar layered deposits in Planum Boreum, we have identified a platform of older, highly degraded polar deposits as much as a kilometer thick that may have once covered an area larger than Planum Boreum. ?? 2001 Elsevier Science.

Microstructures and growth mechanisms of GaN films epitaxially grown on AlN/Si hetero-structures by pulsed laser deposition at different temperatures.

PubMed

Wang, Wenliang; Yang, Weijia; Lin, Yunhao; Zhou, Shizhong; Li, Guoqiang

2015-11-13

2 inch-diameter GaN films with homogeneous thickness distribution have been grown on AlN/Si(111) hetero-structures by pulsed laser deposition (PLD) with laser rastering technique. The surface morphology, crystalline quality, and interfacial property of as-grown GaN films are characterized in detail. By optimizing the laser rastering program, the ~300 nm-thick GaN films grown at 750 °C show a root-mean-square (RMS) thickness inhomogeneity of 3.0%, very smooth surface with a RMS surface roughness of 3.0 nm, full-width at half-maximums (FWHMs) for GaN(0002) and GaN(102) X-ray rocking curves of 0.7° and 0.8°, respectively, and sharp and abrupt AlN/GaN hetero-interfaces. With the increase in the growth temperature from 550 to 850 °C, the surface morphology, crystalline quality, and interfacial property of as-grown ~300 nm-thick GaN films are gradually improved at first and then decreased. Based on the characterizations, the corresponding growth mechanisms of GaN films grown on AlN/Si hetero-structures by PLD with various growth temperatures are hence proposed. This work would be beneficial to understanding the further insight of the GaN films grown on Si(111) substrates by PLD for the application of GaN-based devices.

Controlling particle properties in {{YBa}}_{2}{{Cu}}_{3}{{\\rm{O}}}_{7-\\delta } nanocomposites by combining PLD with an inert gas condensation system

NASA Astrophysics Data System (ADS)

Sparing, M.; Reich, E.; Hänisch, J.; Gottschall, T.; Hühne, R.; Fähler, S.; Rellinghaus, B.; Schultz, L.; Holzapfel, B.

2017-10-01

The critical current density {J}{{c}} in {{YBa}}2{{Cu}}3{{{O}}}7-δ thin films, which limits their application in external magnetic fields, can be enhanced by the introduction of artificial pinning centers such as non-superconducting nanoparticles inducing additional defects and local strain in the superconducting matrix. To understand the correlation between superconductivity, defect structures and particles, a controlled integration of particles with adjustable properties is essential. A powerful technique for the growth of isolated nanoparticles in the range of 10 nm is dc-magnetron sputtering in an inert gas flow. The inert gas condensation (IGC) of particles allows for an independent control of both the particle diameter distribution and the areal density. We report on the integration of such gas-phase-condensed {{HfO}}2 nanoparticles into pulsed laser deposited (PLD) {{YBa}}2{{Cu}}3{{{O}}}7-δ thin film multilayers with a combined PLD-IGC system. The particles and the structure of the multilayers are analyzed by transmission electron microscopy on cross-sectional FIB lamellae. As a result of the IGC particle implementation, randomly as well as biaxially oriented {{BaHfO}}3 precipitates are formed in the {{YBa}}2{{Cu}}3{{{O}}}7-δ thin films. With as few as three interlayers of nanoparticles, the pinning force density is enhanced in the low-field region.

Deinococcus Mn2+ -Peptide Complex: A Novel Approach to Alphavirus Vaccine Development

DTIC Science & Technology

2016-08-05

immunogenicity loss due to oxidative damage to the surface proteins at the high doses of radiation required for complete virus inactivation. Thus, we...bacteria Deinococcus radiodurans) in the present study which selectively protects proteins but not the nucleic acid from the radiation - induced...presence of MDP have significant epitope preservation even at supra-lethal doses of radiation . Irradiated viruses were found to be completely

Moderate DNA damage promotes metabolic flux into PPP via PKM2 Y-105 phosphorylation: a feature that favours cancer cells.

PubMed

Kumar, Bhupender; Bamezai, Rameshwar N K

2015-08-01

Pyruvate kinase M2, an important metabolic enzyme, promotes aerobic glycolysis (Warburg effect) to facilitate cancer cell proliferation. Unravelling the status of this important glycolytic pathway enzyme under sub-lethal doses of etoposide, a commonly used anti-proliferative genotoxic drug to induce mild/moderate DNA damage in HeLa cells as a model system and discern its effect on: PKM2 expression, phosphorylation, dimer: tetramer ratio, activity and associated effects, was pertinent. Protein expression and phosphorylation of PKM2 from HeLa cells was estimated using Western blotting. Same protein lysate was also used to estimate total pyruvate kinase activity and the total dimer: tetramer content evaluated using glycerol gradient ultra-centrifugation. Intracellular PEP was estimated manually using standard curve; while NADPH was assessed by NADPH estimation kit. Unpaired t test and two-way-ANOVA was used for statistical analysis. A relative decrease in PKM2 expression and a subsequent dose and time dependent increase in Y105-phosphorylation were observed. A concomitant increase in PKM2 dimer content and Y105-phosphorylation responsible for reduced PKM2 activity promoted PEP accumulation and NADPH production, representing increased metabolic flux into PPP, a feature that favours cancer cells. It was apparent that the sub-lethal doses of etoposide induced inadequate damage to DNA in cancer cells in culture promoted pro-survival conditions due to Y105-phosphorylation of PKM2, its stable dimerization and inactivation, a unique association not known earlier, indicating what might happen in tumour revivals or recurrences.

Long-term hematopoietic stem cell damage in a murine model of the hematopoietic syndrome of the acute radiation syndrome.

PubMed

Chua, Hui Lin; Plett, P Artur; Sampson, Carol H; Joshi, Mandar; Tabbey, Rebeka; Katz, Barry P; MacVittie, Thomas J; Orschell, Christie M

2012-10-01

Residual bone marrow damage (RBMD) persists for years following exposure to radiation and is believed to be due to decreased self-renewal potential of radiation-damaged hematopoietic stem cells (HSC). Current literature has examined primarily sublethal doses of radiation and time points within a few months of exposure. In this study, the authors examined RBMD in mice surviving lethal doses of total body ionizing irradiation (TBI) in a murine model of the Hematopoietic Syndrome of the Acute Radiation Syndrome (H-ARS). Survivors were analyzed at various time points up to 19 mo post-TBI for hematopoietic function. The competitive bone marrow (BM) repopulating potential of 150 purified c-Kit+ Sca-1+ lineage- CD150+ cells (KSLCD150+) remained severely deficient throughout the study compared to KSLCD150+ cells from non-TBI age-matched controls. The minimal engraftment from these TBI HSCs is predominantly myeloid, with minimal production of lymphocytes both in vitro and in vivo. All classes of blood cells as well as BM cellularity were significantly decreased in TBI mice, especially at later time points as mice aged. Primitive BM hematopoietic cells (KSLCD150+) displayed significantly increased cell cycling in TBI mice at all time points, which may be a physiological attempt to maintain HSC numbers in the post-irradiation state. Taken together, these data suggest that the increased cycling among primitive hematopoietic cells in survivors of lethal radiation may contribute to long-term HSC exhaustion and subsequent RBMD, exacerbated by the added insult of aging at later time points.

Ssb1 and Ssb2 cooperate to regulate mouse hematopoietic stem and progenitor cells by resolving replicative stress.

PubMed

Shi, Wei; Vu, Therese; Boucher, Didier; Biernacka, Anna; Nde, Jules; Pandita, Raj K; Straube, Jasmin; Boyle, Glen M; Al-Ejeh, Fares; Nag, Purba; Jeffery, Jessie; Harris, Janelle L; Bain, Amanda L; Grzelak, Marta; Skrzypczak, Magdalena; Mitra, Abhishek; Dojer, Norbert; Crosetto, Nicola; Cloonan, Nicole; Becherel, Olivier J; Finnie, John; Skaar, Jeffrey R; Walkley, Carl R; Pandita, Tej K; Rowicka, Maga; Ginalski, Krzysztof; Lane, Steven W; Khanna, Kum Kum

2017-05-04

Hematopoietic stem and progenitor cells (HSPCs) are vulnerable to endogenous damage and defects in DNA repair can limit their function. The 2 single-stranded DNA (ssDNA) binding proteins SSB1 and SSB2 are crucial regulators of the DNA damage response; however, their overlapping roles during normal physiology are incompletely understood. We generated mice in which both Ssb1 and Ssb2 were constitutively or conditionally deleted. Constitutive Ssb1/Ssb2 double knockout (DKO) caused early embryonic lethality, whereas conditional Ssb1/Ssb2 double knockout (cDKO) in adult mice resulted in acute lethality due to bone marrow failure and intestinal atrophy featuring stem and progenitor cell depletion, a phenotype unexpected from the previously reported single knockout models of Ssb1 or Ssb2 Mechanistically, cDKO HSPCs showed altered replication fork dynamics, massive accumulation of DNA damage, genome-wide double-strand breaks enriched at Ssb-binding regions and CpG islands, together with the accumulation of R -loops and cytosolic ssDNA. Transcriptional profiling of cDKO HSPCs revealed the activation of p53 and interferon (IFN) pathways, which enforced cell cycling in quiescent HSPCs, resulting in their apoptotic death. The rapid cell death phenotype was reproducible in in vitro cultured cDKO-hematopoietic stem cells, which were significantly rescued by nucleotide supplementation or after depletion of p53. Collectively, Ssb1 and Ssb2 control crucial aspects of HSPC function, including proliferation and survival in vivo by resolving replicative stress to maintain genomic stability. © 2017 by The American Society of Hematology.

Ssb1 and Ssb2 cooperate to regulate mouse hematopoietic stem and progenitor cells by resolving replicative stress

PubMed Central

Vu, Therese; Boucher, Didier; Biernacka, Anna; Nde, Jules; Pandita, Raj K.; Straube, Jasmin; Boyle, Glen M.; Al-Ejeh, Fares; Jeffery, Jessie; Harris, Janelle L.; Bain, Amanda L.; Grzelak, Marta; Skrzypczak, Magdalena; Mitra, Abhishek; Dojer, Norbert; Crosetto, Nicola; Cloonan, Nicole; Becherel, Olivier J.; Finnie, John; Skaar, Jeffrey R.; Walkley, Carl R.; Pandita, Tej K.; Rowicka, Maga; Ginalski, Krzysztof

2017-01-01

Hematopoietic stem and progenitor cells (HSPCs) are vulnerable to endogenous damage and defects in DNA repair can limit their function. The 2 single-stranded DNA (ssDNA) binding proteins SSB1 and SSB2 are crucial regulators of the DNA damage response; however, their overlapping roles during normal physiology are incompletely understood. We generated mice in which both Ssb1 and Ssb2 were constitutively or conditionally deleted. Constitutive Ssb1/Ssb2 double knockout (DKO) caused early embryonic lethality, whereas conditional Ssb1/Ssb2 double knockout (cDKO) in adult mice resulted in acute lethality due to bone marrow failure and intestinal atrophy featuring stem and progenitor cell depletion, a phenotype unexpected from the previously reported single knockout models of Ssb1 or Ssb2. Mechanistically, cDKO HSPCs showed altered replication fork dynamics, massive accumulation of DNA damage, genome-wide double-strand breaks enriched at Ssb-binding regions and CpG islands, together with the accumulation of R-loops and cytosolic ssDNA. Transcriptional profiling of cDKO HSPCs revealed the activation of p53 and interferon (IFN) pathways, which enforced cell cycling in quiescent HSPCs, resulting in their apoptotic death. The rapid cell death phenotype was reproducible in in vitro cultured cDKO-hematopoietic stem cells, which were significantly rescued by nucleotide supplementation or after depletion of p53. Collectively, Ssb1 and Ssb2 control crucial aspects of HSPC function, including proliferation and survival in vivo by resolving replicative stress to maintain genomic stability. PMID:28270450

Caffeine-enhanced survival of radiation-sensitive, repair-deficient Chinese hamster cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Utsumi, H.; Elkind, M.M.

1983-11-01

A clone of V79 Chinese hamster cells (V79-AL162/S-10) with unique properties has been isolated after a challenge of parental cells (V79-AL162) with 1 mM ouabain. Compared with parental cells, or with other clones isolated after the ouabain challenge, these cells form smaller colonies, are more sensitive to both x rays and fission-spectrum neutrons, and respond atypically to a postirradiation treatment with caffeine. Their enhanced response to x rays results mainly from a large reduction in the shoulder of their survival curve, probably because in late S phase, the most resistant phase in the cell cycle, the survival curve of thesemore » cells has a reduced shoulder width. Caffeine, and to a lesser extent theophylline, added to the colony-forming medium immediately after exposure appreciably increases the width of the shoulder of these sensitive cells, whereas caffeine has the opposite effect on the response of normal V79 cells. Thus the unique response of the V79-AL162/S-10 cells to a radiation posttreatment with caffeine (increased survival) results from a net increase in their ability to repair damage that is otherwise lethal; caffeine treatment ordinarly prevents normal V79 cells from repairing damage that is only potentially lethal.« less

Action of caffeine on x-irradiated HeLa cells. VII. Evidence that caffeine enhances expression of potentially lethal radiation damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beetham, K.L.; Tolmach, L.J.

1984-12-01

HeLa cells irradiated with 2 Gy of 220-kV X rays suffer a 60-70% loss of colony-forming ability which is increased to 90% by postirradiation treatment with 10 mM caffeine for 6 hr. The detailed postirradiation patterns of cell death and sister-cell fusion in such cultures and in cultures in which the colony-forming ability was brought to about the same level by treatment with a larger (4 Gy) X-ray dose alone or by longer (48 hr) treatment with 10 mM caffeine alone were recorded by time-lapse cinemicrography. Because the patterns of cell death and fusion differ radically in irradiated and inmore » caffeine-treated cultures, the response of the additional cells killed by the combined treatment can be identified as X-ray induced rather than caffeine induced. The appearance of cultures after several days of incubation confirms the similarity of the post-treatment patterns of proliferation in cultures suffering enhanced killing to those occurring in cultures treated with larger doses of X rays alone. It is concluded that x rays do not sensitize cells to caffeine, but rather that caffeine enhanced the expression of potentially lethal radiation-induced damage.« less

New estimates of lethality of sea lamprey (Petromyzon marinus) attacks on lake trout (Salvelinus namaycush): Implications for fisheries management

USGS Publications Warehouse

Madenjian, C.P.; Chipman, B.D.; Marsden, J.E.

2008-01-01

Sea lamprey (Petromyzon marinus) control in North America costs millions of dollars each year, and control measures are guided by assessment of lamprey-induced damage to fisheries. The favored prey of sea lamprey in freshwater ecosystems has been lake trout (Salvelinus namaycush). A key parameter in assessing sea lamprey damage, as well as managing lake trout fisheries, is the probability of an adult lake trout surviving a lamprey attack. The conventional value for this parameter has been 0.55, based on laboratory experiments. In contrast, based on catch curve analysis, mark-recapture techniques, and observed wounding rates, we estimated that adult lake trout in Lake Champlain have a 0.74 probability of surviving a lamprey attack. Although sea lamprey growth in Lake Champlain was lower than that observed in Lake Huron, application of an individual-based model to both lakes indicated that the probability of surviving an attack in Lake Champlain was only 1.1 times higher than that in Lake Huron. Thus, we estimated that lake trout survive a lamprey attack in Lake Huron with a probability of 0.66. Therefore, our results suggested that lethality of a sea lamprey attack on lake trout has been overestimated in previous model applications used in fisheries management. ?? 2008 NRC.

Coffee mitigates cyclophosphamide-induced genotoxic damage in Drosophila melanogaster germ cells.

PubMed

Nagpal, Isha; Abraham, Suresh K

2018-02-26

In the present study, coffee (CF) was evaluated for its protective effects against genotoxic damage and oxidative stress induced by the chemotherapeutic drug, cyclophosphamide (CPH). The sex-linked recessive lethal (SLRL) test was employed to study the induction of mutations in the larvae as well as in all the successive germ cell stages of treated males. Control and treated third instar larvae were used to monitor the biomarkers of oxidative stress response such as glutathione content (GSH), glutathione-S-transferase (GST), catalase (CAT), superoxide dismutase (SOD) and lipid peroxidation (MDA content). Our results demonstrated that co-administration of CF (2%) with CPH (3 mM) has significantly reduced CPH-induced lethal mutations in the germ cells of larvae and adult flies. The reductions observed in mutation frequencies were: 75% in larvae and 62.4% in the adult. Significant enhancement in antioxidant enzymatic levels: CAT (46.6%) > SOD (43.0%) > GST (42.4%) > GSH (31.6%) and reduction in MDA levels (32.05%) in the pretreated third instar larvae demonstrated the antioxidant activity of CF against CPH-induced oxidative stress. The findings from the present study suggest that the Drosophila model is an ideal one for evaluating the antigenotoxic and antioxidant activity of complex mixtures like CF.

Inferring the distribution of mutational effects on fitness in Drosophila.

PubMed

Loewe, Laurence; Charlesworth, Brian

2006-09-22

The properties of the distribution of deleterious mutational effects on fitness (DDME) are of fundamental importance for evolutionary genetics. Since it is extremely difficult to determine the nature of this distribution, several methods using various assumptions about the DDME have been developed, for the purpose of parameter estimation. We apply a newly developed method to DNA sequence polymorphism data from two Drosophila species and compare estimates of the parameters of the distribution of the heterozygous fitness effects of amino acid mutations for several different distribution functions. The results exclude normal and gamma distributions, since these predict too few effectively lethal mutations and power-law distributions as a result of predicting too many lethals. Only the lognormal distribution appears to fit both the diversity data and the frequency of lethals. This DDME arises naturally in complex systems when independent factors contribute multiplicatively to an increase in fitness-reducing damage. Several important parameters, such as the fraction of effectively neutral non-synonymous mutations and the harmonic mean of non-neutral selection coefficients, are robust to the form of the DDME. Our results suggest that the majority of non-synonymous mutations in Drosophila are under effective purifying selection.

Thermodynamic guiding principles in selective synthesis of strontium iridate Ruddlesden-Popper epitaxial Films

DOE PAGES

Nishio, Kazunori; Hwang, Harold Y.; Hikita, Yasuyuki

2016-03-10

We demonstrate the selective fabrication of Ruddlesden-Popper (RP) type SrIrO 3, Sr 3Ir 2O 7, and Sr 2IrO 4 epitaxialthin films from a single SrIrO 3 target using pulsed laser deposition(PLD). We identified that the growth conditions stabilizing each phase directly map onto the phase diagram expected from thermodynamic equilibria. This approach allows precise cation stoichiometry control as evidenced by the stabilization of single phase Sr 3Ir 2O 7 for the first time, overcoming the close thermodynamic stability between neighboring RP phases. Furthermore, despite the non-equilibrium nature of PLD, these results highlight the importance of thermodynamic guiding principles to strategicallymore » synthesize the targeted phase in complex oxide thin films.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ying, Minju, E-mail: mjying@bnu.edu.cn, E-mail: g.gehring@sheffield.ac.uk; Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875; Blythe, Harry J.

We investigate the magnetic properties of ZnCoO thin films grown by pulsed laser deposition (PLD) from targets made containing metallic Co or CoO precursors instead of the usual Co{sub 3}O{sub 4}. We find that the films grown from metallic Co precursors in an oxygen rich environment contain negligible amounts of Co metal and have a large magnetization at room temperature. Structural analysis by X-ray diffraction and magneto-optical measurements indicate that the enhanced magnetism is due, in part, from Zn vacancies that partially compensate the naturally occurring n-type defects. We conclude that strongly magnetic films of Zn{sub 0.95}Co{sub 0.05}O that domore » not contain metallic cobalt can be grown by PLD from Co-metal-precursor targets if the films are grown in an oxygen atmosphere.« less

Phase-selective vanadium dioxide (VO2) nanostructured thin films by pulsed laser deposition

NASA Astrophysics Data System (ADS)

Masina, B. N.; Lafane, S.; Wu, L.; Akande, A. A.; Mwakikunga, B.; Abdelli-Messaci, S.; Kerdja, T.; Forbes, A.

2015-10-01

Thin films of monoclinic nanostructured vanadium dioxide are notoriously difficult to produce in a selective manner. To date, post-annealing, after pulsed laser deposition (PLD), has been used to revert the crystal phase or to remove impurities, and non-glass substrates have been employed, thus reducing the efficacy of the transparency switching. Here, we overcome these limitations in PLD by optimizing a laser-ablation and deposition process through optical imaging of the laser-induced plasma. We report high quality monoclinic rutile-type vanadium dioxide (VO2) (M1) nanoparticles without post-annealing, and on a glass substrate. Our samples demonstrate a reversible metal-to-insulator transition at ˜43 °C, without any doping, paving the way to switchable transparency in optical materials at room temperature.

Apparatus and method for pulsed laser deposition of materials on wires and pipes

DOEpatents

Fernandez, Felix E.

2003-01-01

Methods and apparatuses are disclosed which allow uniform coatings to be applied by pulsed laser deposition (PLD) on inner and outer surfaces of cylindrical objects, such as rods, pipes, tubes, and wires. The use of PLD makes this technique particularly suitable for complex multicomponent materials, such as superconducting ceramics. Rigid objects of any length, i.e., pipes up to a few meters, and with diameters from less than 1 centimeter to over 10 centimeters can be coated using this technique. Further, deposition is effected simultaneously onto an annular region of the pipe wall. This particular arrangement simplifies the apparatus, reduces film uniformity control difficulties, and can result in faster operation cycles. In addition, flexible wires of any length can be continuously coated using the disclosed invention.

Local Real-Space View of the Achiral 1 T -TiSe2 2 ×2 ×2 Charge Density Wave

NASA Astrophysics Data System (ADS)

Hildebrand, B.; Jaouen, T.; Mottas, M.-L.; Monney, G.; Barreteau, C.; Giannini, E.; Bowler, D. R.; Aebi, P.

2018-03-01

The transition metal dichalcogenide 1 T -TiSe2 -two-dimensional layered material undergoing a commensurate 2 ×2 ×2 charge density wave (CDW) transition with a weak periodic lattice distortion (PLD) below ≈200 K . Scanning tunneling microscopy (STM) combined with intentionally introduced interstitial Ti atoms allows us to go beyond the usual spatial resolution of STM and to intimately probe the three-dimensional character of the PLD. Furthermore, the inversion-symmetric achiral nature of the CDW in the z direction is revealed, contradicting the claimed existence of helical CDW stacking and associated chiral order. This study paves the way to a simultaneous real-space probing of both charge and structural reconstructions in CDW compounds.

Immunolocalization of a glycosylphosphatidylinositol-specific phospholipase D in mast cells found in normal tissue and neurofibromatosis lesions.

PubMed

Metz, C N; Thomas, P; Davitz, M A

1992-06-01

A large number of eukaryotic proteins have been shown to be anchored to the cell membrane by glycosylphosphatidylinositol (GPI). This glycolipid anchor can serve as a substrate for anchor-specific phospholipases that convert the GPI-anchored membrane proteins into soluble forms. Soluble forms of many GPI anchored proteins have been identified in vivo in connective tissue, plasma, and urine. The authors have discovered that mammalian plasma contains a GPI-specific phospholipase D (GPI-PLD). Because it recognizes a portion of the conserved glycan core structure, all GPI-anchored proteins are potential substrates. The authors report the development of a murine monoclonal antibody specific for one form of the human GPI-PLD and the immunohistochemical localization of this enzyme to mast cells.

Influence of amorphous structure on polymorphism in vanadia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stone, Kevin H.; Schelhas, Laura T.; Garten, Lauren M.

Normally we think of the glassy state as a single phase and therefore crystallization from chemically identical amorphous precursors should be identical. Here we show that the local structure of an amorphous precursor is distinct depending on the initial deposition conditions, resulting in significant differences in the final state material. Using grazing incidence total x-ray scattering, we have determined the local structure in amorphous thin films of vanadium oxide grown under different conditions using pulsed laser deposition (PLD). Here we show that the subsequent crystallization of films deposited using different initial PLD conditions result in the formation of different polymorphsmore » of VO 2. Ultimately this suggests the possibility of controlling the formation of metastable polymorphs by tuning the initial amorphous structure to different formation pathways.« less

Influence of amorphous structure on polymorphism in vanadia

DOE PAGES

Stone, Kevin H.; Schelhas, Laura T.; Garten, Lauren M.; ...

2016-07-13

Normally we think of the glassy state as a single phase and therefore crystallization from chemically identical amorphous precursors should be identical. Here we show that the local structure of an amorphous precursor is distinct depending on the initial deposition conditions, resulting in significant differences in the final state material. Using grazing incidence total x-ray scattering, we have determined the local structure in amorphous thin films of vanadium oxide grown under different conditions using pulsed laser deposition (PLD). Here we show that the subsequent crystallization of films deposited using different initial PLD conditions result in the formation of different polymorphsmore » of VO 2. Ultimately this suggests the possibility of controlling the formation of metastable polymorphs by tuning the initial amorphous structure to different formation pathways.« less

Comparative study of LaNiO3/LaAlO3 heterostructures grown by pulsed laser deposition and oxide molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Wrobel, F.; Mark, A. F.; Christiani, G.; Sigle, W.; Habermeier, H.-U.; van Aken, P. A.; Logvenov, G.; Keimer, B.; Benckiser, E.

2017-01-01

Variations in growth conditions associated with different deposition techniques can greatly affect the phase stability and defect structure of complex oxide heterostructures. We synthesized superlattices of the paramagnetic metal LaNiO3 and the large band gap insulator LaAlO3 by atomic layer-by-layer molecular beam epitaxy (MBE) and pulsed laser deposition (PLD) and compared their crystallinity and microstructure as revealed by high-resolution transmission electron microscopy images and resistivity. The MBE samples show a higher density of stacking faults but smoother interfaces and generally higher electrical conductivity. Our study identifies the opportunities and challenges of MBE and PLD growth and serves as a general guide for the choice of the deposition technique for perovskite oxides.

Surface diffusion in homoepitaxial SrTiO3 thin films

NASA Astrophysics Data System (ADS)

Woo, Chang-Su; Chu, Kanghyun; Song, Jong-Hyun; Yang, Chan-Ho; Charm Lab Team; Nano Spintronics Lab Collaboration

The development of growth techniques such as molecular beam epitaxy (MBE) and pulsed laser deposition (PLD) has facilitated growths of complex oxide thin films at the atomic level .... Systematic studies on surface diffusion process of adatoms using theoretical and experimental methods allow us to understand growth mechanism enabling atomically flat thin film surface. In this presentation, we introduce the synthesis of homoepitaxial SrTiO3 thin films using a PLD equipped with reflection of high energy electron diffraction (RHEED). We determine the surface diffusion time as a function of growth temperature and extract the activation energy of diffusion on the surface by in-situ monitoring the RHEED intensity recovery during the film deposition. From the extracted experimental results, we discuss the microscopic mechanism of the diffusion process

A novel regulation mechanism of DNA repair by damage-induced and RAD23-dependent stabilization of xeroderma pigmentosum group C protein

PubMed Central

Ng, Jessica M.Y.; Vermeulen, Wim; van der Horst, Gijsbertus T.J.; Bergink, Steven; Sugasawa, Kaoru; Vrieling, Harry; Hoeijmakers, Jan H.J.

2003-01-01

Primary DNA damage sensing in mammalian global genome nucleotide excision repair (GG-NER) is performed by the xeroderma pigmentosum group C (XPC)/HR23B protein complex. HR23B and HR23A are human homologs of the yeast ubiquitin-domain repair factor RAD23, the function of which is unknown. Knockout mice revealed that mHR23A and mHR23B have a fully redundant role in NER, and a partially redundant function in embryonic development. Inactivation of both genes causes embryonic lethality, but appeared still compatible with cellular viability. Analysis of mHR23A/B double-mutant cells showed that HR23 proteins function in NER by governing XPC stability via partial protection against proteasomal degradation. Interestingly, NER-type DNA damage further stabilizes XPC and thereby enhances repair. These findings resolve the primary function of RAD23 in repair and reveal a novel DNA-damage-dependent regulation mechanism of DNA repair in eukaryotes, which may be part of a more global damage-response circuitry. PMID:12815074

Time-dependent lethal body residues for the toxicity of pentachlorobenzene to Hyalella azteca

USGS Publications Warehouse

Landrum, Peter F.; Steevens, Jeffery A.; Gossiaux, Duane C.; McElroy, Michael; Robinson, Sander; Begnoche, Linda; Chernyak, Sergei; Hickey, James

2004-01-01

The study examined the temporal response of Hyalella azteca to pentachlorobenzene (PCBZ) in water-only exposures. Toxicity was evaluated by calculating the body residue of PCBZ associated with survival. The concentration of PCBZ in the tissues of H. azteca associated with 50% mortality decreased from 3 to 0.5 μmol/g over the temporal range of 1 to 28 d, respectively. No significant difference was observed in the body residue calculated for 50% mortality when the value was determined using live or dead organisms. Metabolism of PCBZ was not responsible for the temporal response because no detectable PCBZ biotransformation occurred over an exposure period of 10 d. A damage assessment model was used to evaluate the impact and repair of damage by PCBZ on H. azteca. The toxicokinetics were determined so that the temporal toxicity data could be fit to a damage assessment model. The half-life calculated for the elimination of PCBZ averaged approximately 49 h, while the value determined for the half-life of damage repair from the damage assessment model was 33 h.

Radiation induced failures of complementary metal oxide semiconductor containing pacemakers: a potentially lethal complication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewin, A.A.; Serago, C.F.; Schwade, J.G.

1984-10-01

New multi-programmable pacemakers frequently employ complementary metal oxide semiconductors (CMOS). This circuitry appears more sensitive to the effects of ionizing radiation when compared to the semiconductor circuits used in older pacemakers. A case of radiation induced runaway pacemaker in a CMOS device is described. Because of this and other recent reports of radiation therapy-induced CMOS type pacemaker failure, these pacemakers should not be irradiated. If necessary, the pacemaker can be shielded or moved to a site which can be shielded before institution of radiation therapy. This is done to prevent damage to the CMOS circuit and the life threatening arrythmiasmore » which may result from such damage.« less

MASM, a Matrine Derivative, Offers Radioprotection by Modulating Lethal Total-Body Irradiation-Induced Multiple Signaling Pathways in Wistar Rats.

PubMed

Li, Jianzhong; Xu, Jing; Lu, Yiming; Qiu, Lei; Xu, Weiheng; Lu, Bin; Hu, Zhenlin; Chu, Zhiyong; Chai, Yifeng; Zhang, Junping

2016-05-17

Matrine is an alkaloid extracted from Sophora flavescens Ait and has many biological activities, such as anti-inflammatory, antitumor, anti-fibrosis, and immunosuppressive properties. In our previous studies, the matrine derivative MASM was synthesized and exhibited potent inhibitory activity against liver fibrosis. In this study, we mainly investigated its protection against lethal total-body irradiation (TBI) in rats. Administration of MASM reduced the radiation sickness characteristics and increased the 30-day survival of rats before or after lethal TBI. Ultrastructural observation illustrated that pretreatment of rats with MASM significantly attenuated the TBI-induced morphological changes in the different organs of irradiated rats. Gene expression profiles revealed that pretreatment with MASM had a dramatic effect on gene expression changes caused by TBI. Pretreatment with MASM prevented differential expression of 53% (765 genes) of 1445 differentially expressed genes induced by TBI. Pathway enrichment analysis indicated that these genes were mainly involved in a total of 21 pathways, such as metabolic pathways, pathways in cancer, and mitogen-activated protein kinase (MAPK) pathways. Our data indicated that pretreatment of rats with MASM modulated these pathways induced by TBI, suggesting that the pretreatment with MASM might provide the protective effects on lethal TBI mainly or partially through the modulation of these pathways, such as multiple MAPK pathways. Therefore, MASM has the potential to be used as an effective therapeutic or radioprotective agent to minimize irradiation damages and in combination with radiotherapy to improve the efficacy of cancer therapy.

Metabolic Response of Escherichia coli upon Treatment with Hypochlorite at Sub-Lethal Concentrations

PubMed Central

Winter, Jeannette; Eisenreich, Wolfgang

2015-01-01

Hypochlorite is a reactive oxygen species that is worldwide as an antibacterial disinfectant. Hypochlorite exposure is known to cause oxidative damage to DNA and proteins. As a response to these effects, the metabolite profiles of organisms treated with sub-lethal doses of hypochlorite are assumed to be severely modified; however, the nature of these changes is hardly understood. Therefore, using nuclear magnetic resonance spectroscopy and gas chromatography-coupled mass spectrometry, we analyzed the time-dependent impact of hypochlorite exposure with a sub-lethal concentration (50 µM) on the metabolite profile of the Escherichia coli strain MG1655. Principle component analysis clearly distinguished between the metabolite profiles of bacteria treated for 0, 5,10, 20, 40, or 60 min. Major changes in the relative amounts of fatty acids, acetic acid, and formic acid occurred within the first 5 min. Comparative gas chromatography-coupled mass spectrometry analyses revealed that the amounts of free methionine and alanine were significantly decreased in the treated cells, demonstrating their susceptibility to hypochlorite exposure. The concentrations of succinate, urea, orotic acid, 2-aminobutyric acid, and 2-hydroxybutyric acid were also severely affected, indicating general changes in the metabolic network by hypochlorite. However, most metabolite levels relaxed to the reference values of untreated cells after 40–60 min, reflecting the capability of E. coli to rapidly adapt to environmental stress factors such as the presence of sub-lethal oxidant levels. PMID:25932918

Mutation at p53 serine 389 does not rescue the embryonic lethality in mdm2 or mdm4 null mice.

PubMed

Iwakuma, Tomoo; Parant, John M; Fasulo, Mark; Zwart, Edwin; Jacks, Tyler; de Vries, Annemieke; Lozano, Guillermina

2004-10-07

Mdm2 and its homolog Mdm4 inhibit the function of the tumor suppressor p53. Targeted disruption of either mdm2 or mdm4 genes in mice results in embryonic lethality that is completely rescued by concomitant deletion of p53, suggesting that deletion of negative regulators of p53 results in a constitutively active p53. Thus, these mouse models offer a unique in vivo system to assay the functional significance of different p53 modifications. Phosphorylation of serine 389 in murine p53 occurs specifically after ultraviolet-light-induced DNA damage, and phosphorylation of this site enhances p53 activity both in vitro and in vivo. Recently, mice with a serine to alanine substitution at serine 389 (p53S389A) in the endogenous p53 locus were generated. To examine the in vivo significance of serine 389 phosphorylation during embryogenesis, we crossed these mutant mice to mice lacking mdm2 or mdm4. The p53S389A allele did not alter the embryonic lethality of mdm2 or mdm4. Additional crosses to assay the effect of one p53S389A allele with a p53 null allele also did not rescue the lethal phenotypes. In conclusion, the phenotypes due to loss of mdm2 or mdm4 were not even partially rescued by p53S389A, suggesting that p53S389A is functionally wild type during embryogenesis.

Revealing buried craters in the Martian polar layered deposits using three-dimensional radar imaging

NASA Astrophysics Data System (ADS)

Perry, M. R.; Putzig, N. E.; Smith, I. B.; Foss, F. J., II; Campbell, B. A.

2017-12-01

Constraining the age of the polar layered deposits (PLD) is paramount to our understanding of the climate evolution of Mars. Other than climate models, direct observational evidence that can be used to constrain ages has been largely limited to surface cratering statistics. The Shallow Radar (SHARAD) sounder aboard the Mars Reconnaissance Orbiter (MRO) has been observing the polar regions of Mars since late 2006. With over 3000 individual observations to date at each pole, the radar data have been instrumental in revealing the internal features of the PLD (Phillips et al., 2008; Putzig et al. 2009; Holt et al., 2010; Smith et al., 2010; Brothers et al., 2015), discovering buried structures and estimating the volume of both H2O and newly found CO2 ices (Phillips et al., 2011; Bierson et al,. 2016). Yet despite these achievements, 2D radargrams from individual orbit passes do not allow the clear delineation of craters within or below the deposits, thus limiting our ability to date the PLDs or their individual layers. Using a 3D volume derived from thousands of intersecting 2D observations (Foss et al., 2017; Putzig et al., in rev.), we present preliminary results that uncover craters buried beneath the PLDs. In the north, we have identified 21 apparent craters at the base of the PLD ranging in diameter from 7 to 45 km. The cumulative size-frequency distribution of these craters matches well with that of surface craters in the surrounding regions. This result lends support to the prior interpretation from radar mapping that the surfaces on which the NPLD sits consist of basal units and an expected extension of Vastitas Borealis materials that are both dated as Hesperian, about 3.8 Ga old. Moreover, the consistency between the buried and exposed surface ages bolsters the interpretation of the buried circular features seen in the radar volumes as impact craters. Work is still ongoing to identify craters at the base of the SPLD as well as craters within the PLD.

Glycerophosphodiester phosphodiesterase domain containing 5 (GDPD5) expression correlates with malignant choline phospholipid metabolite profiles in human breast cancer

PubMed Central

Cao, Maria D.; Döpkens, Mailin; Krishnamachary, Balaji; Vesuna, Farhad; Gadiya, Mayur M.; Loenning, Per E.; Bhujwalla, Zaver M.; Gribbestad, Ingrid S.; Glunde, Kristine

2012-01-01

Altered choline phospholipid metabolism is a hallmark of cancer, leading to malignant choline metabolite profiles consisting of low glycerophosphocholine (GPC) and high phosphocholine (PC) in human breast cancers. Glycerophosphocholine phosphodiesterase (GPC-PDE) catalyzes the degradation of GPC to free choline and glycerol-3-phosphate. The gene(s) encoding for the GPC-PDE(s) responsible for GPC degradation in breast cancers have not yet been identified. Here we have demonstrated for the first time that the GPC-PDE encoded by glycerophosphodiester phosphodiesterase domain containing 5 (GDPD5) is associated with breast cancer malignancy. Two human breast cancer cell lines (n=8 and 10) and primary human breast tumor samples (n=19) were studied with combined magnetic resonance spectroscopy (MRS) and qRT-PCR to investigate several isoforms of GDPD expression with respect to choline phospholipid metabolite levels. Out of five GDPDs tested, GDPD5 was found to be significantly overexpressed in highly malignant estrogen receptor negative (ER−) compared to weakly malignant estrogen receptor positive (ER+) human breast cancer cells (P=0.027) and breast tumors from patients (P=0.015). GDPD5 showed significantly positive correlations with PC (P<0.001), total choline (tCho) (P=0.007) and PC/GPC (P<0.001) levels in human breast tumors. GDPD5 showed a trend towards negative correlation with GPC levels (P=0.130). Human breast cancers with malignant choline metabolite profiles consisting of low GPC and high PC levels highly co-expressed GDPD5, choline kinase alpha (CHKA), and phosphatidylcholine-specific phospholipase D1 (PLD1), while cancers containing high GPC and relatively low PC levels displayed low co-expression of GDPD5, CHKA, and PLD1. GDPD5, CHKA and PLD1 were significantly overexpressed in highly malignant ER− tumors in our patient cohort. Our study identified GDPD5 as a GPC-PDE that likely participates in regulating choline phospholipid metabolism in breast cancer, which possibly occurs in cooperation with CHKA and PLD1. PMID:22279038

Genetic doping and health damages.

PubMed

Fallahi, Aa; Ravasi, Aa; Farhud, Dd

2011-01-01

Use of genetic doping or gene transfer technology will be the newest and the lethal method of doping in future and have some unpleasant consequences for sports, athletes, and outcomes of competitions. The World Anti-Doping Agency (WADA) defines genetic doping as "the non-therapeutic use of genes, genetic elements, and/or cells that have the capacity to enhance athletic performance ". The purpose of this review is to consider genetic doping, health damages and risks of new genes if delivered in athletes. This review, which is carried out by reviewing relevant publications, is primarily based on the journals available in GOOGLE, ELSEVIER, PUBMED in fields of genetic technology, and health using a combination of keywords (e.g., genetic doping, genes, exercise, performance, athletes) until July 2010. There are several genes related to sport performance and if they are used, they will have health risks and sever damages such as cancer, autoimmunization, and heart attack.

Genetic Doping and Health Damages

PubMed Central

Fallahi, AA; Ravasi, AA; Farhud, DD

2011-01-01

Background: Use of genetic doping or gene transfer technology will be the newest and the lethal method of doping in future and have some unpleasant consequences for sports, athletes, and outcomes of competitions. The World Anti-Doping Agency (WADA) defines genetic doping as “the non-therapeutic use of genes, genetic elements, and/or cells that have the capacity to enhance athletic performance ”. The purpose of this review is to consider genetic doping, health damages and risks of new genes if delivered in athletes. Methods: This review, which is carried out by reviewing relevant publications, is primarily based on the journals available in GOOGLE, ELSEVIER, PUBMED in fields of genetic technology, and health using a combination of keywords (e.g., genetic doping, genes, exercise, performance, athletes) until July 2010. Conclusion: There are several genes related to sport performance and if they are used, they will have health risks and sever damages such as cancer, autoimmunization, and heart attack. PMID:23113049

Divergent Roles of RPA Homologs of the Model Archaeon Halobacterium salinarum in Survival of DNA Damage.

PubMed

Evans, Jessica J; Gygli, Patrick E; McCaskill, Julienne; DeVeaux, Linda C

2018-04-20

The haloarchaea are unusual in possessing genes for multiple homologs to the ubiquitous single-stranded DNA binding protein (SSB or replication protein A, RPA) found in all three domains of life. Halobacterium salinarum contains five homologs: two are eukaryotic in organization, two are prokaryotic and are encoded on the minichromosomes, and one is uniquely euryarchaeal. Radiation-resistant mutants previously isolated show upregulation of one of the eukaryotic-type RPA genes. Here, we have created deletions in the five RPA operons. These deletion mutants were exposed to DNA-damaging conditions: ionizing radiation, UV radiation, and mitomycin C. Deletion of the euryarchaeal homolog, although not lethal as in Haloferax volcanii , causes severe sensitivity to all of these agents. Deletion of the other RPA/SSB homologs imparts a variable sensitivity to these DNA-damaging agents, suggesting that the different RPA homologs have specialized roles depending on the type of genomic insult encountered.

Unsolved mysteries: How does lipid peroxidation cause ferroptosis?

PubMed Central

Feng, Huizhong

2018-01-01

Ferroptosis is a cell death process driven by damage to cell membranes and linked to numerous human diseases. Ferroptosis is caused by loss of activity of the key enzyme that is tasked with repairing oxidative damage to cell membranes—glutathione peroxidase 4 (GPX4). GPX4 normally removes the dangerous products of iron-dependent lipid peroxidation, protecting cell membranes from this type of damage; when GPX4 fails, ferroptosis ensues. Ferroptosis is distinct from apoptosis, necroptosis, necrosis, and other modes of cell death. Several key mysteries regarding how cells die during ferroptosis remain unsolved. First, the drivers of lipid peroxidation are not yet clear. Second, the subcellular location of lethal lipid peroxides remains an outstanding question. Finally, how exactly lipid peroxidation leads to cell death is an unsolved mystery. Answers to these questions will provide insights into the mechanisms of ferroptotic cell death and associated human diseases, as well as new therapeutic strategies for such diseases. PMID:29795546

Case-study of fatal gunshot wounds from non-lethal projectiles.

PubMed

Chowaniec, Czesław; Kobek, Mariusz; Jabłoński, Christian; Kabiesz-Neniczka, Stanisława; Karczewska, Weronika

2008-07-04

The authors present a case of the death of a 60-year-old man shot using rubber projectiles that were fired by a police officer from a Mossberg smooth-bore shotgun in an enclosed space from a distance of a few metres. The post-mortem examination revealed that death had been due to gunshot wounds in the chest which had caused heart and lung damage with subsequent massive internal haemorrhaging.

America’s Achilles Heel: Defense Against High-altitude Electromagnetic Pulse-policy vs. Practice

DTIC Science & Technology

2014-12-12

Directives SCADA Supervisory Control and Data Acquisition Systems SHIELD Act Secure High-voltage Infrastructure for Electricity from Lethal Damage Act...take place, it is important to understand the effects of the components of EMP from a high-altitude nuclear detonation. The requirements for shielding ...Mass Ejection (CME). A massive, bubble-shaped burst of plasma expanding outward from the Sun’s corona, in which large amounts of superheated

Structural Basis of Mec1-Ddc2-RPA Assembly and Activation on Single-Stranded DNA at Sites of Damage.

PubMed

Deshpande, Ishan; Seeber, Andrew; Shimada, Kenji; Keusch, Jeremy J; Gut, Heinz; Gasser, Susan M

2017-10-19

Mec1-Ddc2 (ATR-ATRIP) is a key DNA-damage-sensing kinase that is recruited through the single-stranded (ss) DNA-binding replication protein A (RPA) to initiate the DNA damage checkpoint response. Activation of ATR-ATRIP in the absence of DNA damage is lethal. Therefore, it is important that damage-specific recruitment precedes kinase activation, which is achieved at least in part by Mec1-Ddc2 homodimerization. Here, we report a structural, biochemical, and functional characterization of the yeast Mec1-Ddc2-RPA assembly. High-resolution co-crystal structures of Ddc2-Rfa1 and Ddc2-Rfa1-t11 (K45E mutant) N termini and of the Ddc2 coiled-coil domain (CCD) provide insight into Mec1-Ddc2 homodimerization and damage-site targeting. Based on our structural and functional findings, we present a Mec1-Ddc2-RPA-ssDNA composite structural model. By way of validation, we show that RPA-dependent recruitment of Mec1-Ddc2 is crucial for maintaining its homodimeric state at ssDNA and that Ddc2's recruitment domain and CCD are important for Mec1-dependent survival of UV-light-induced DNA damage. Copyright © 2017 Elsevier Inc. All rights reserved.

Repair-dependent cell radiation survival and transformation: an integrated theory.

PubMed

Sutherland, John C

2014-09-07

The repair-dependent model of cell radiation survival is extended to include radiation-induced transformations. The probability of transformation is presumed to scale with the number of potentially lethal damages that are repaired in a surviving cell or the interactions of such damages. The theory predicts that at doses corresponding to high survival, the transformation frequency is the sum of simple polynomial functions of dose; linear, quadratic, etc, essentially as described in widely used linear-quadratic expressions. At high doses, corresponding to low survival, the ratio of transformed to surviving cells asymptotically approaches an upper limit. The low dose fundamental- and high dose plateau domains are separated by a downwardly concave transition region. Published transformation data for mammalian cells show the high-dose plateaus predicted by the repair-dependent model for both ultraviolet and ionizing radiation. For the neoplastic transformation experiments that were analyzed, the data can be fit with only the repair-dependent quadratic function. At low doses, the transformation frequency is strictly quadratic, but becomes sigmodial over a wider range of doses. Inclusion of data from the transition region in a traditional linear-quadratic analysis of neoplastic transformation frequency data can exaggerate the magnitude of, or create the appearance of, a linear component. Quantitative analysis of survival and transformation data shows good agreement for ultraviolet radiation; the shapes of the transformation components can be predicted from survival data. For ionizing radiations, both neutrons and x-rays, survival data overestimate the transforming ability for low to moderate doses. The presumed cause of this difference is that, unlike UV photons, a single x-ray or neutron may generate more than one lethal damage in a cell, so the distribution of such damages in the population is not accurately described by Poisson statistics. However, the complete sigmodial dose-response data for neoplastic transformations can be fit using the repair-dependent functions with all parameters determined only from transformation frequency data.

Alternative forms of lethality in mitomycin C-induced bacteria carrying ColE1 plasmids

PubMed Central

Suit, Joan L.; Fan, M.-L. Judy; Sabik, Joseph F.; Labarre, Robert; Luria, S. E.

1983-01-01

We have studied the physiological effects of mitomycin C induction on cells carrying ColE1 plasmids with differing configurations of three genes: the structural gene coding for colicin (cea), a gene responsible for mitomycin C lethality (kil) that we located as part of an operon with cea, and the immunity (imm) gene, which lies near cea but is not in the same operon. kil is close to or overlaps imm. When cea+ plasmids are present mitomycin C induction results in 100-fold or greater increases in the level of colicin. Within an hour after induction more than 90% of cells carrying cea+kil+ plasmids are killed and macromolecular synthesis stops, capacity for transport of proline, thiomethyl β-D-galactoside, and α-methyl glucoside is lost, and the membrane becomes abnormally permeable as indicated by an increased accessibility of intracellular β-galactosidase to the substrate o-nitrophenyl β-D-galactoside. All of these events occur when a cea-kil+imm+ plasmid is present and none does when the plasmid is cea+kil-imm+, so the damage can be attributed solely to the Kil function and not to the presence of colicin. However, cells carrying a cea+kil-imm- plasmid are killed upon induction, apparently by action of endogenous colicin on the nonimmune cytoplasmic membrane. The pattern of accompanying physiological damage is distinguished from the kil+-associated damage by an enhancement of α-methyl glucoside uptake and accumulation and efflux of α-methyl glucoside 6-phosphate and by an absence of the alteration in membrane permeability for o-nitrophenyl β-D-galactoside. These features are typical of colicin E1 action on the membrane. The induced damage is not prevented by trypsin and occurs in cells of a strain specifically tolerant to exogenous colicin E1, indicating that the attack is from inside the cell. PMID:6403939

Cancer risk coefficient for patient undergoing kyphoplasty surgery using Monte Carlo method

NASA Astrophysics Data System (ADS)

Santos, Felipe A.; Santos, William S.; Galeano, Diego C.; Cavalcante, Fernanda R.; Silva, Ademir X.; Souza, Susana O.; Júnior, Albérico B. Carvalho

2017-11-01

Kyphoplasty surgery is widely used for pain relief in patients with vertebral compression fracture (VCF). For this surgery, an X-ray emitter that provides real-time imaging is employed to guide the medical instruments and the surgical cement used to fill and strengthen the vertebra. Equivalent and effective doses related to high temporal resolution equipment has been studied to assess the damage and more recently cancer risk. For this study, a virtual scenario was prepared using MCNPX code and a pair of UF family simulators. Two projections with seven tube voltages for each one were simulated. The organ in the abdominal region were those who had higher cancer risk because they receive the primary beam. The risk of lethal cancer is on average 20% higher in AP projection than in LL projection. This study aims at estimating the risk of cancer in organs and the risk of lethal cancer for patient submitted to kyphoplasty surgery.

Fentanyl novel derivative-related deaths.

PubMed

Giorgetti, Arianna; Centola, Carmela; Giorgetti, Raffaele

2017-05-01

Fentanyl (FEN) is a potent, synthetic narcotic used as an anaesthetic and a pain reliever, but also illegally manufactured. For diversion purpose, it is being steadily modified to produce new analogous compounds and derivatives (FENS), categorised as novel psychoactive substances. While potential FEN abuse is already known, even in the absence of a clear lethal dosage, there is still a shortage of data on its derivatives. A literature review of FENS-related deaths was performed, to better understand potential damage and future perspectives of FEN congeners. Epidemiological data, pathological findings, administration routes, average concentrations and lethal doses, toxicological issues, trends in misuses, comparison among FENS, and possible explanation for FENS abuse are reviewed and discussed in depth. This study provides a medical-legal and toxicological assessment of this phenomenon in order to understand the role of illegal fentanyl and its congeners in deaths from FENS overdose. Copyright © 2017 John Wiley & Sons, Ltd.

Novel insights for systemic inflammation in sepsis and hemorrhage.

PubMed

Cai, Bolin; Deitch, Edwin A; Ulloa, Luis

2010-01-01

The inflammatory responses in sepsis and hemorrhage remain a major cause of death. Clinically, it is generally accepted that shock in sepsis or hemorrhage differs in its mechanisms. However, the recognition of inflammatory cytokines as a common lethal pathway has become consent. Proinflammatory cytokines such as tumor necrosis factor (TNF) or high-mobility group box1 (HMGB1) are fanatically released and cause lethal multiorgan dysfunction. Inhibition of these cytokines can prevent the inflammatory responses and organ damage. In seeking potential anti-inflammatory strategies, we reported that ethyl pyruvate and alpha7 nicotinic acetylcholine receptor (alpha7nAChR) agonists effectively restrained cytokine production to provide therapeutic benefits in both experimental sepsis and hemorrhage. Here, we review the inflammatory responses and the anti-inflammatory strategies in experimental models of sepsis and hemorrhage, as they may have a consistent inflammatory pathway in spite of their different pathophysiological processes.

Dynamic in vivo imaging of small animal brain using pulsed laser diode-based photoacoustic tomography system.

PubMed

Upputuri, Paul Kumar; Pramanik, Manojit

2017-09-01

We demonstrate dynamic in vivo imaging using a low-cost portable pulsed laser diode (PLD)-based photoacoustic tomography system. The system takes advantage of an 803-nm PLD having high-repetition rate ∼7000  Hz combined with a fast-scanning single-element ultrasound transducer leading to a 5 s cross-sectional imaging. Cortical vasculature is imaged in scan time of 5 s with high signal-to-noise ratio ∼48. To examine the ability for dynamic imaging, we monitored the fast uptake and clearance process of indocyanine green in the rat brain. The system will find applications to study neurofunctional activities, characterization of pharmacokinetic, and biodistribution profiles in the development process of drugs or imaging agents. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Phase-selective vanadium dioxide (VO{sub 2}) nanostructured thin films by pulsed laser deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masina, B. N., E-mail: BMasina@csir.co.za, E-mail: slafane@cdta.dz; School of Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000; Lafane, S., E-mail: BMasina@csir.co.za, E-mail: slafane@cdta.dz

2015-10-28

Thin films of monoclinic nanostructured vanadium dioxide are notoriously difficult to produce in a selective manner. To date, post-annealing, after pulsed laser deposition (PLD), has been used to revert the crystal phase or to remove impurities, and non-glass substrates have been employed, thus reducing the efficacy of the transparency switching. Here, we overcome these limitations in PLD by optimizing a laser-ablation and deposition process through optical imaging of the laser-induced plasma. We report high quality monoclinic rutile-type vanadium dioxide (VO{sub 2}) (M1) nanoparticles without post-annealing, and on a glass substrate. Our samples demonstrate a reversible metal-to-insulator transition at ∼43 °C, withoutmore » any doping, paving the way to switchable transparency in optical materials at room temperature.« less

Performance of magnetoelectric PZT/Ni multiferroic system for energy harvesting application

NASA Astrophysics Data System (ADS)

Gupta, Reema; Tomar, Monika; Kumar, Ashok; Gupta, Vinay

2017-03-01

Magnetoelectric (ME) coefficient of Lead Zirconium Titanate (PZT) thin films has been probed for possible energy harvesting applications. Single phase PZT thin films have been deposited on nickel substrate (PZT/Ni) using pulsed laser deposition (PLD) technique. The effect of PLD process parameters on the ME coupling coefficient in the prepared systems has been investigated. The as grown PZT films on Ni substrate were found to be polycrystalline with improved ferroelectric and ferromagnetic properties. The electrical switching behavior of the PZT thin films were verified using capacitance voltage measurements, where well defined butterfly loops were obtained. The ME coupling coefficient was estimated to be in the range of 94.5 V cm-1 Oe-1-130.5 V cm-1 Oe-1 for PZT/Ni system, which is large enough for harnessing electromagnetic energy for subsequent applications.

Persistent photocurrent and deep level traps in PLD-grown In-Ga-Zn-O thin films studied by thermally stimulated current spectroscopy

NASA Astrophysics Data System (ADS)

Wang, Buguo; Anders, Jason; Leedy, Kevin; Schuette, Michael; Look, David

2018-02-01

InGaZnO (IGZO) is a promising semiconductor material for thin-film transistors (TFTs) used in DC and RF switching applications, especially since it can be grown at low temperatures on a wide variety of substrates. Enhancement-mode TFTs based on IGZO thin films grown by pulsed laser deposition (PLD) have been recently fabricated and these transistors show excellent performance; however, compositional variations and defects can adversely affect film quality, especially in regard to electrical properties. In this study, we use thermally stimulated current (TSC) spectroscopy to characterize the electrical properties and the deep traps in PLD-grown IGZO thin films. It was found that the as-grown sample has a DC activation energy of 0.62 eV, and two major traps with activation energies at 0.16-0.26 eV and at 0.90 eV. However, a strong persistent photocurrent (PPC) sometimes exists in the as-grown sample, so we carry out post-growth annealing in an attempt to mitigate the effect. It was found that annealing in argon increases the conduction, produces more PPC and also makes more traps observable. Annealing in air makes the film more resistive, and removes PPC and all traps but one. This work demonstrates that current-based trap emission, such as that associated with the TSC, can effectively reveal electronic defects in highlyresistive semiconductor materials, especially those are not amenable to capacitance-based techniques, such as deeplevel transient spectroscopy (DLTS).

Phospholipase D and phosphatidic acid in plant defence response: from protein–protein and lipid–protein interactions to hormone signalling

PubMed Central

Zhao, Jian

2015-01-01

Phospholipase Ds (PLDs) and PLD-derived phosphatidic acids (PAs) play vital roles in plant hormonal and environmental responses and various cellular dynamics. Recent studies have further expanded the functions of PLDs and PAs into plant–microbe interaction. The molecular diversities and redundant functions make PLD–PA an important signalling complex regulating lipid metabolism, cytoskeleton dynamics, vesicle trafficking, and hormonal signalling in plant defence through protein–protein and protein–lipid interactions or hormone signalling. Different PLD–PA signalling complexes and their targets have emerged as fast-growing research topics for understanding their numerous but not yet established roles in modifying pathogen perception, signal transduction, and downstream defence responses. Meanwhile, advanced lipidomics tools have allowed researchers to reveal further the mechanisms of PLD–PA signalling complexes in regulating lipid metabolism and signalling, and their impacts on jasmonic acid/oxylipins, salicylic acid, and other hormone signalling pathways that essentially mediate plant defence responses. This review attempts to summarize the progress made in spatial and temporal PLD/PA signalling as well as PLD/PA-mediated modification of plant defence. It presents an in-depth discussion on the functions and potential mechanisms of PLD–PA complexes in regulating actin filament/microtubule cytoskeleton, vesicle trafficking, and hormonal signalling, and in influencing lipid metabolism-derived metabolites as critical signalling components in plant defence responses. The discussion puts PLD–PA in a broader context in order to guide future research. PMID:25680793

Orexin A Inhibits Propofol-Induced Neurite Retraction by a Phospholipase D/Protein Kinase Cε-Dependent Mechanism in Neurons

PubMed Central

Björnström, Karin; Turina, Dean; Strid, Tobias; Sundqvist, Tommy; Eintrei, Christina

2014-01-01

Background The intravenous anaesthetic propofol retracts neurites and reverses the transport of vesicles in rat cortical neurons. Orexin A (OA) is an endogenous neuropeptide regulating wakefulness and may counterbalance anaesthesia. We aim to investigate if OA interacts with anaesthetics by inhibition of the propofol-induced neurite retraction. Methods In primary cortical cell cultures from newborn rats’ brains, live cell light microscopy was used to measure neurite retraction after propofol (2 µM) treatment with or without OA (10 nM) application. The intracellular signalling involved was tested using a protein kinase C (PKC) activator [phorbol 12-myristate 13-acetate (PMA)] and inhibitors of Rho-kinase (HA-1077), phospholipase D (PLD) [5-fluoro-2-indolyl des-chlorohalopemide (FIPI)], PKC (staurosporine), and a PKCε translocation inhibitor peptide. Changes in PKCε Ser729 phosphorylation were detected with Western blot. Results The neurite retraction induced by propofol is blocked by Rho-kinase and PMA. OA blocks neurite retraction induced by propofol, and this inhibitory effect could be prevented by FIPI, staurosporine and PKCε translocation inhibitor peptide. OA increases via PLD and propofol decreases PKCε Ser729 phosphorylation, a crucial step in the activation of PKCε. Conclusions Rho-kinase is essential for propofol-induced neurite retraction in cortical neuronal cells. Activation of PKC inhibits neurite retraction caused by propofol. OA blocks propofol-induced neurite retraction by a PLD/PKCε-mediated pathway, and PKCε maybe the key enzyme where the wakefulness and anaesthesia signal pathways converge. PMID:24828410

Enhancement of automated blood flow estimates (ENABLE) from arterial spin-labeled MRI.

PubMed

Shirzadi, Zahra; Stefanovic, Bojana; Chappell, Michael A; Ramirez, Joel; Schwindt, Graeme; Masellis, Mario; Black, Sandra E; MacIntosh, Bradley J

2018-03-01

To validate a multiparametric automated algorithm-ENhancement of Automated Blood fLow Estimates (ENABLE)-that identifies useful and poor arterial spin-labeled (ASL) difference images in multiple postlabeling delay (PLD) acquisitions and thereby improve clinical ASL. ENABLE is a sort/check algorithm that uses a linear combination of ASL quality features. ENABLE uses simulations to determine quality weighting factors based on an unconstrained nonlinear optimization. We acquired a set of 6-PLD ASL images with 1.5T or 3.0T systems among 98 healthy elderly and adults with mild cognitive impairment or dementia. We contrasted signal-to-noise ratio (SNR) of cerebral blood flow (CBF) images obtained with ENABLE vs. conventional ASL analysis. In a subgroup, we validated our CBF estimates with single-photon emission computed tomography (SPECT) CBF images. ENABLE produced significantly increased SNR compared to a conventional ASL analysis (Wilcoxon signed-rank test, P < 0.0001). We also found the similarity between ASL and SPECT was greater when using ENABLE vs. conventional ASL analysis (n = 51, Wilcoxon signed-rank test, P < 0.0001) and this similarity was strongly related to ASL SNR (t = 24, P < 0.0001). These findings suggest that ENABLE improves CBF image quality from multiple PLD ASL in dementia cohorts at either 1.5T or 3.0T, achieved by multiparametric quality features that guided postprocessing of dementia ASL. 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:647-655. © 2017 International Society for Magnetic Resonance in Medicine.

Microstructures and growth mechanisms of GaN films epitaxially grown on AlN/Si hetero-structures by pulsed laser deposition at different temperatures

PubMed Central

Wang, Wenliang; Yang, Weijia; Lin, Yunhao; Zhou, Shizhong; Li, Guoqiang

2015-01-01

2 inch-diameter GaN films with homogeneous thickness distribution have been grown on AlN/Si(111) hetero-structures by pulsed laser deposition (PLD) with laser rastering technique. The surface morphology, crystalline quality, and interfacial property of as-grown GaN films are characterized in detail. By optimizing the laser rastering program, the ~300 nm-thick GaN films grown at 750 °C show a root-mean-square (RMS) thickness inhomogeneity of 3.0%, very smooth surface with a RMS surface roughness of 3.0 nm, full-width at half-maximums (FWHMs) for GaN(0002) and GaN(102) X-ray rocking curves of 0.7° and 0.8°, respectively, and sharp and abrupt AlN/GaN hetero-interfaces. With the increase in the growth temperature from 550 to 850 °C, the surface morphology, crystalline quality, and interfacial property of as-grown ~300 nm-thick GaN films are gradually improved at first and then decreased. Based on the characterizations, the corresponding growth mechanisms of GaN films grown on AlN/Si hetero-structures by PLD with various growth temperatures are hence proposed. This work would be beneficial to understanding the further insight of the GaN films grown on Si(111) substrates by PLD for the application of GaN-based devices. PMID:26563573

Phase II Study of Bortezomib and Pegylated Liposomal Doxorubicin in the Treatment of Metastatic Breast Cancer

PubMed Central

Irvin, William J.; Orlowski, Robert Z.; Chiu, Wing-Keung; Carey, Lisa A.; Collichio, Frances A.; Bernard, Philip S.; Stijleman, Inge J.; Perou, Charles; Ivanova, Anastasia; Dees, E. Claire

2018-01-01

Background Based on preclinical studies and a phase I trial of the combination of bortezomib and pegylated liposomal doxorubicin (PLD), which both showed activity in breast cancer, we conducted a phase II study of this regimen in patients with metastatic breast cancer. Patients and Methods Patients received bortezomib 1.3 mg/m2 on days 1, 4, 8, and 11 of an every-21-day cycle, along with PLD 30 mg/m2 on day 4. The primary objective was to evaluate the response rate of this combination, while secondary objectives were to obtain further safety data about this combination, to evaluate the time to disease progression (TTP), and to evaluate response by the breast cancer subtype. Results One of 12 evaluable patients had a partial response (8%), while 3 (25%) had stable disease. At 26 months follow-up, the median overall survival was 4.3 months (95% CI, 1.2–26.2) and the median TTP was 1.3 months (95% CI, 0.8–14.0 months). The combination was well tolerated, with the most common events including low-grade nausea and vomiting, neutropenia, and neuropathy, and no cardiac toxicity was seen. Of the 7 tumors subtyped, no association was seen between intrinsic subtype or receptor status and response. Conclusion The combination of PLD and bortezomib was well tolerated but has minimal activity in heavily pretreated unselected metastatic breast cancer. PMID:21147690

Membrane Tension Acts Through PLD2 and mTORC2 to Limit Actin Network Assembly During Neutrophil Migration

PubMed Central

Diz-Muñoz, Alba; Thurley, Kevin; Chintamen, Sana; Altschuler, Steven J.; Fletcher, Daniel A.; Weiner, Orion D.

2016-01-01

For efficient polarity and migration, cells need to regulate the magnitude and spatial distribution of actin assembly. This process is coordinated by reciprocal interactions between the actin cytoskeleton and mechanical forces. Actin polymerization-based protrusion increases tension in the plasma membrane, which in turn acts as a long-range inhibitor of actin assembly. These interactions form a negative feedback circuit that limits the magnitude of membrane tension in neutrophils and prevents expansion of the existing front and the formation of secondary fronts. It has been suggested that the plasma membrane directly inhibits actin assembly by serving as a physical barrier that opposes protrusion. Here we show that efficient control of actin polymerization-based protrusion requires an additional mechanosensory feedback cascade that indirectly links membrane tension with actin assembly. Specifically, elevated membrane tension acts through phospholipase D2 (PLD2) and the mammalian target of rapamycin complex 2 (mTORC2) to limit actin nucleation. In the absence of this pathway, neutrophils exhibit larger leading edges, higher membrane tension, and profoundly defective chemotaxis. Mathematical modeling suggests roles for both the direct (mechanical) and indirect (biochemical via PLD2 and mTORC2) feedback loops in organizing cell polarity and motility—the indirect loop is better suited to enable competition between fronts, whereas the direct loop helps spatially organize actin nucleation for efficient leading edge formation and cell movement. This circuit is essential for polarity, motility, and the control of membrane tension. PMID:27280401

Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

NASA Astrophysics Data System (ADS)

Aronne, Antonio; Bloisi, Francesco; Calabria, Raffaela; Califano, Valeria; Depero, Laura E.; Fanelli, Esther; Federici, Stefania; Massoli, Patrizio; Vicari, Luciano R. M.

2015-05-01

Lipase is an enzyme that finds application in biodiesel production and for detection of esters and triglycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial application, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence.

Clustered DNA damages induced in isolated DNA and in human cells by low doses of ionizing radiation

NASA Technical Reports Server (NTRS)

Sutherland, B. M.; Bennett, P. V.; Sidorkina, O.; Laval, J.; Lowenstein, D. I. (Principal Investigator)

2000-01-01

Clustered DNA damages-two or more closely spaced damages (strand breaks, abasic sites, or oxidized bases) on opposing strands-are suspects as critical lesions producing lethal and mutagenic effects of ionizing radiation. However, as a result of the lack of methods for measuring damage clusters induced by ionizing radiation in genomic DNA, neither the frequencies of their production by physiological doses of radiation, nor their repairability, nor their biological effects are known. On the basis of methods that we developed for quantitating damages in large DNAs, we have devised and validated a way of measuring ionizing radiation-induced clustered lesions in genomic DNA, including DNA from human cells. DNA is treated with an endonuclease that induces a single-strand cleavage at an oxidized base or abasic site. If there are two closely spaced damages on opposing strands, such cleavage will reduce the size of the DNA on a nondenaturing gel. We show that ionizing radiation does induce clustered DNA damages containing abasic sites, oxidized purines, or oxidized pyrimidines. Further, the frequency of each of these cluster classes is comparable to that of frank double-strand breaks; among all complex damages induced by ionizing radiation, double-strand breaks are only about 20%, with other clustered damage constituting some 80%. We also show that even low doses (0.1-1 Gy) of high linear energy transfer ionizing radiation induce clustered damages in human cells.

Chronic exposure to graphene-based nanomaterials induces behavioral deficits and neural damage in Caenorhabditis elegans.

PubMed

Li, Ping; Xu, Tiantian; Wu, Siyu; Lei, Lili; He, Defu

2017-10-01

Nanomaterials of graphene and its derivatives have been widely applied in recent years, but whose impacts on the environment and health are still not well understood. In the present study, the potential adverse effects of graphite (G), graphite oxide nanoplatelets (GO) and graphene quantum dots (GQDs) on the motor nervous system were investigated using nematode Caenorhabditis elegans as the assay system. After being characterized using TEM, SEM, XPS and PLE, three nanomaterials were chronically exposed to C. elegans for 6 days. In total, 50-100 mg l -1 GO caused a significant reduction in the survival rate, but G and GDDs showed low lethality on nematodes. After chronic exposure of sub-lethal dosages, three nanomaterials were observed to distribute primarily in the pharynx and intestine; but GQDs were widespread in nematode body. Three graphene-based nanomaterials resulted in significant declines in locomotor frequency of body bending, head thrashing and pharynx pumping. In addition, mean speed, bending angle-frequency and wavelength of the crawling movement were significantly reduced after exposure. Using transgenic nematodes, we found high concentrations of graphene-based nanomaterials induced down-expression of dat-1::GFP and eat-4::GFP, but no significant changes in unc-47::GFP. This indicates that graphene-based nanomaterials can lead to damages in the dopaminergic and glutamatergic neurons. The present data suggest that chronic exposure of graphene-based nanomaterials may cause neurotoxicity risks of inducing behavioral deficits and neural damage. These findings provide useful information to understand the toxicity and safe application of graphene-based nanomaterials. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Interplay between high energy impulse noise (blast) and antioxidants in the lung.

PubMed

Elsayed, Nabil M; Gorbunov, Nikolai V

2003-07-15

High-energy impulse noise (BLAST) is a physical event characterized by an abrupt rise in atmospheric pressure above ambient lasting for a very short period, but potentially causing significant material and biological damage. Exposure to high-level BLAST can be destructive and lethal. Low-level BLAST similar to what is encountered repeatedly by military personnel during training and combat from detonation of munitions and firing of large caliber weapons, and during occupational use of explosives and some heavy machinery, can also cause significant injury. Globally, civilians are increasingly exposed to BLAST resulting from terrorist bombings or abandoned unmarked mines following numerous wars and conflicts. We have shown previously in several animal models that exposure to non-lethal BLAST results in pathological changes, mostly to the hollow organs characterized in the lungs, the most sensitive organ, by rupture of alveolar septa, and pulmonary hemorrhage and edema. These events potentially can cause alveolar flooding, respiratory insufficiency and adult respiratory distress syndrome (ARDS), leading to varying degrees of hypoxia, antioxidant depletion and oxidative damage. We have also observed progressive formation of nitric oxide in blood and other tissues. The totality of these observations supports our general hypothesis that exposure to BLAST can lead to antioxidant depletion and oxidative damage. Understanding the mechanism(s) of BLAST-induced oxidative stress may have important implications that include a potential beneficial role for antioxidants as a prophylaxis or as secondary treatment of injury after exposure alongside other protective and therapeutic modalities. In addition, it suggests a role for endogenous nitric oxide in the injury. This report reviews experimental evidence of BLAST-induced antioxidant depletion, and the potential benefit from antioxidant supplementation before exposure.

RpoS Plays a Central Role in the SOS Induction by Sub-Lethal Aminoglycoside Concentrations in Vibrio cholerae

PubMed Central

Baharoglu, Zeynep; Krin, Evelyne; Mazel, Didier

2013-01-01

Bacteria encounter sub-inhibitory concentrations of antibiotics in various niches, where these low doses play a key role for antibiotic resistance selection. However, the physiological effects of these sub-lethal concentrations and their observed connection to the cellular mechanisms generating genetic diversification are still poorly understood. It is known that, unlike for the model bacterium Escherichia coli, sub-minimal inhibitory concentrations (sub-MIC) of aminoglycosides (AGs) induce the SOS response in Vibrio cholerae. SOS is induced upon DNA damage, and since AGs do not directly target DNA, we addressed two issues in this study: how sub-MIC AGs induce SOS in V. cholerae and why they do not do so in E. coli. We found that when bacteria are grown with tobramycin at a concentration 100-fold below the MIC, intracellular reactive oxygen species strongly increase in V. cholerae but not in E. coli. Using flow cytometry and gfp fusions with the SOS regulated promoter of intIA, we followed AG-dependent SOS induction. Testing the different mutation repair pathways, we found that over-expression of the base excision repair (BER) pathway protein MutY relieved this SOS induction in V. cholerae, suggesting a role for oxidized guanine in AG-mediated indirect DNA damage. As a corollary, we established that a BER pathway deficient E. coli strain induces SOS in response to sub-MIC AGs. We finally demonstrate that the RpoS general stress regulator prevents oxidative stress-mediated DNA damage formation in E. coli. We further show that AG-mediated SOS induction is conserved among the distantly related Gram negative pathogens Klebsiella pneumoniae and Photorhabdus luminescens, suggesting that E. coli is more of an exception than a paradigm for the physiological response to antibiotics sub-MIC. PMID:23613664

RpoS plays a central role in the SOS induction by sub-lethal aminoglycoside concentrations in Vibrio cholerae.

PubMed

Baharoglu, Zeynep; Krin, Evelyne; Mazel, Didier

2013-01-01

Bacteria encounter sub-inhibitory concentrations of antibiotics in various niches, where these low doses play a key role for antibiotic resistance selection. However, the physiological effects of these sub-lethal concentrations and their observed connection to the cellular mechanisms generating genetic diversification are still poorly understood. It is known that, unlike for the model bacterium Escherichia coli, sub-minimal inhibitory concentrations (sub-MIC) of aminoglycosides (AGs) induce the SOS response in Vibrio cholerae. SOS is induced upon DNA damage, and since AGs do not directly target DNA, we addressed two issues in this study: how sub-MIC AGs induce SOS in V. cholerae and why they do not do so in E. coli. We found that when bacteria are grown with tobramycin at a concentration 100-fold below the MIC, intracellular reactive oxygen species strongly increase in V. cholerae but not in E. coli. Using flow cytometry and gfp fusions with the SOS regulated promoter of intIA, we followed AG-dependent SOS induction. Testing the different mutation repair pathways, we found that over-expression of the base excision repair (BER) pathway protein MutY relieved this SOS induction in V. cholerae, suggesting a role for oxidized guanine in AG-mediated indirect DNA damage. As a corollary, we established that a BER pathway deficient E. coli strain induces SOS in response to sub-MIC AGs. We finally demonstrate that the RpoS general stress regulator prevents oxidative stress-mediated DNA damage formation in E. coli. We further show that AG-mediated SOS induction is conserved among the distantly related Gram negative pathogens Klebsiella pneumoniae and Photorhabdus luminescens, suggesting that E. coli is more of an exception than a paradigm for the physiological response to antibiotics sub-MIC.

Exploiting Drug Addiction Mechanisms to Select against MAPKi-Resistant Melanoma.

PubMed

Hong, Aayoung; Moriceau, Gatien; Sun, Lu; Lomeli, Shirley; Piva, Marco; Damoiseaux, Robert; Holmen, Sheri L; Sharpless, Norman E; Hugo, Willy; Lo, Roger S

2018-01-01

Melanoma resistant to MAPK inhibitors (MAPKi) displays loss of fitness upon experimental MAPKi withdrawal and, clinically, may be resensitized to MAPKi therapy after a drug holiday. Here, we uncovered and therapeutically exploited the mechanisms of MAPKi addiction in MAPKi-resistant BRAF MUT or NRAS MUT melanoma. MAPKi-addiction phenotypes evident upon drug withdrawal spanned transient cell-cycle slowdown to cell-death responses, the latter of which required a robust phosphorylated ERK (pERK) rebound. Generally, drug withdrawal-induced pERK rebound upregulated p38-FRA1-JUNB-CDKN1A and downregulated proliferation, but only a robust pERK rebound resulted in DNA damage and parthanatos-related cell death. Importantly, pharmacologically impairing DNA damage repair during MAPKi withdrawal augmented MAPKi addiction across the board by converting a cell-cycle deceleration to a caspase-dependent cell-death response or by furthering parthanatos-related cell death. Specifically in MEKi-resistant NRAS MUT or atypical BRAF MUT melanoma, treatment with a type I RAF inhibitor intensified pERK rebound elicited by MEKi withdrawal, thereby promoting a cell death-predominant MAPKi-addiction phenotype. Thus, MAPKi discontinuation upon disease progression should be coupled with specific strategies that augment MAPKi addiction. Significance: Discontinuing targeted therapy may select against drug-resistant tumor clones, but drug-addiction mechanisms are ill-defined. Using melanoma resistant to but withdrawn from MAPKi, we defined a synthetic lethality between supraphysiologic levels of pERK and DNA damage. Actively promoting this synthetic lethality could rationalize sequential/rotational regimens that address evolving vulnerabilities. Cancer Discov; 8(1); 74-93. ©2017 AACR. See related commentary by Stern, p. 20 This article is highlighted in the In This Issue feature, p. 1 . ©2017 American Association for Cancer Research.

Plasma Bacterial and Mitochondrial DNA Distinguish Bacterial Sepsis from Sterile SIRS and Quantify Inflammatory Tissue Injury in Nonhuman Primates

PubMed Central

Sursal, Tolga; Stearns-Kurosawa, Deborah J; Itagaki, Kiyoshi; Oh, Sun-Young; Sun, Shiqin; Kurosawa, Shinichiro; Hauser, Carl J

2012-01-01

Systemic inflammatory response syndrome (SIRS) is a fundamental host response common to bacterial infection and sterile tissue injury. SIRS can cause organ dysfunction and death but its mechanisms are incompletely understood. Moreover, SIRS can progress to organ failure or death despite being sterile or after control of the inciting infection. Biomarkers discriminating between sepsis, sterile SIRS and post-infective SIRS would therefore help direct care. Circulating mitochondrial DNA (mtDNA) is a damage-associated molecular pattern (DAMP) reflecting cellular injury. Circulating bacterial 16S-DNA (bDNA) is a pathogen-associated pattern (PAMP) reflecting ongoing infection. We developed qPCR assays to quantify these markers and predicted their plasma levels might help distinguish sterile injury from infection. To study these events in primates we assayed banked serum from papio baboons that had undergone a brief challenge of intravenous Bacillus anthracis deltaSterne (modified to remove toxins) followed by antibiotics (anthrax) that causes organ failure and death. To investigate the progression of sepsis to “severe” sepsis and death we studied animals where anthrax was pretreated with drotrecogin alfa (aPC), which attenuates sepsis in baboons. We also contrasted lethal anthrax bacteremia against non-lethal E.coli bacteremia and against sterile tissue injury from Shiga-like toxin-1 (Stx1). bDNA and mtDNA levels in timed samples were correlated with blood culture results and assays of organ function. Sterile injury by Stx1 increased mtDNA but bDNA was undetectable: consistent with the absence of infection. The bacterial challenges caused parallel early bDNA and mtDNA increases, but bDNA detected pathogens even after bacteria were undetectable by culture. Sub-lethal E.coli challenge only caused transient rises in mtDNA consistent with a self-limited injury. In lethal anthrax challenge (n=4) bDNA increased transiently but mtDNA levels remained elevated until death, consistent with persistent septic tissue damage after bacterial clearance. Critically, aPC pre-treatment (n=4) allowed mtDNA levels to decay after bacterial clearance with sparing of organ function and survival. In summary, host tissue injury correlates with mtDNA whether infective or sterile. mtDNA and bDNA PCRs can quantify tissue injury incurred by septic or sterile mechanisms and suggest the source of SIRS of unknown origin. PMID:23247122

Acetaminophen-Induced Liver Injury Alters the Acyl Ethanolamine-Based Anti-Inflammatory Signaling System in Liver.

PubMed

Rivera, Patricia; Pastor, Antoni; Arrabal, Sergio; Decara, Juan; Vargas, Antonio; Sánchez-Marín, Laura; Pavón, Francisco J; Serrano, Antonia; Bautista, Dolores; Boronat, Anna; de la Torre, Rafael; Baixeras, Elena; Lucena, M Isabel; de Fonseca, Fernando R; Suárez, Juan

2017-01-01

Protective mechanisms against drug-induced liver injury are actively being searched to identify new therapeutic targets. Among them, the anti-inflammatory N -acyl ethanolamide (NAE)-peroxisome proliferators activated receptor alpha (PPARα) system has gained much interest after the identification of its protective role in steatohepatitis and liver fibrosis. An overdose of paracetamol (APAP), a commonly used analgesic/antipyretic drug, causes hepatotoxicity, and it is being used as a liver model. In the present study, we have analyzed the impact of APAP on the liver NAE-PPARα system. A dose-response (0.5-5-10-20 mM) and time-course (2-6-24 h) study in human HepG2 cells showed a biphasic response, with a decreased PPAR α expression after 6-h APAP incubation followed by a generalized increase of NAE-PPARα system-related components ( PPAR α, NAPE-PLD , and FAAH ), including the NAEs oleoyl ethanolamide (OEA) and docosahexaenoyl ethanolamide, after a 24-h exposure to APAP. These results were partially confirmed in a time-course study of mice exposed to an acute dose of APAP (750 mg/kg). The gene expression levels of Ppar α and Faah were decreased after 6 h of treatment and, after 24 h, the gene expression levels of Nape-pld and Faah , as well as the liver levels of OEA and palmitoyl ethanolamide, were increased. Repeated APAP administration (750 mg/kg/day) up to 4 days also decreased the expression levels of PPARα and FAAH, and increased the liver levels of NAEs. A resting period of 15 days completely restored these impairments. Liver immunohistochemistry in a well-characterized human case of APAP hepatotoxicity confirmed PPARα and FAAH decrements. Histopathological and hepatic damage ( Cyp2e1, Caspase3 , α Sma, Tnf α, and Mcp1 )-related alterations observed after repeated APAP administration were aggravated in the liver of Ppar α-deficient mice. Our results demonstrate that the anti-inflammatory NAE-PPARα signaling system is implicated in liver toxicity after exposure to APAP overdose, and may contribute to its recovery through a long-term time-dependent response.

Acetaminophen-Induced Liver Injury Alters the Acyl Ethanolamine-Based Anti-Inflammatory Signaling System in Liver

PubMed Central

Rivera, Patricia; Pastor, Antoni; Arrabal, Sergio; Decara, Juan; Vargas, Antonio; Sánchez-Marín, Laura; Pavón, Francisco J.; Serrano, Antonia; Bautista, Dolores; Boronat, Anna; de la Torre, Rafael; Baixeras, Elena; Lucena, M. Isabel; de Fonseca, Fernando R.; Suárez, Juan

2017-01-01

Protective mechanisms against drug-induced liver injury are actively being searched to identify new therapeutic targets. Among them, the anti-inflammatory N-acyl ethanolamide (NAE)-peroxisome proliferators activated receptor alpha (PPARα) system has gained much interest after the identification of its protective role in steatohepatitis and liver fibrosis. An overdose of paracetamol (APAP), a commonly used analgesic/antipyretic drug, causes hepatotoxicity, and it is being used as a liver model. In the present study, we have analyzed the impact of APAP on the liver NAE-PPARα system. A dose-response (0.5–5–10–20 mM) and time-course (2–6–24 h) study in human HepG2 cells showed a biphasic response, with a decreased PPARα expression after 6-h APAP incubation followed by a generalized increase of NAE-PPARα system-related components (PPARα, NAPE-PLD, and FAAH), including the NAEs oleoyl ethanolamide (OEA) and docosahexaenoyl ethanolamide, after a 24-h exposure to APAP. These results were partially confirmed in a time-course study of mice exposed to an acute dose of APAP (750 mg/kg). The gene expression levels of Pparα and Faah were decreased after 6 h of treatment and, after 24 h, the gene expression levels of Nape-pld and Faah, as well as the liver levels of OEA and palmitoyl ethanolamide, were increased. Repeated APAP administration (750 mg/kg/day) up to 4 days also decreased the expression levels of PPARα and FAAH, and increased the liver levels of NAEs. A resting period of 15 days completely restored these impairments. Liver immunohistochemistry in a well-characterized human case of APAP hepatotoxicity confirmed PPARα and FAAH decrements. Histopathological and hepatic damage (Cyp2e1, Caspase3, αSma, Tnfα, and Mcp1)-related alterations observed after repeated APAP administration were aggravated in the liver of Pparα-deficient mice. Our results demonstrate that the anti-inflammatory NAE-PPARα signaling system is implicated in liver toxicity after exposure to APAP overdose, and may contribute to its recovery through a long-term time-dependent response. PMID:29056914

The Evolving MCART Multimodal Imaging Core: Establishing a protocol for Computed Tomography and Echocardiography in the Rhesus macaque to perform longitudinal analysis of radiation-induced organ injury

PubMed Central

de Faria, Eduardo B.; Barrow, Kory R.; Ruehle, Bradley T.; Parker, Jordan T.; Swartz, Elisa; Taylor-Howell, Cheryl; Kieta, Kaitlyn M.; Lees, Cynthia J.; Sleeper, Meg M.; Dobbin, Travis; Baron, Adam D.; Mohindra, Pranshu; MacVittie, Thomas J.

2015-01-01

Computed Tomography (CT) and Echocardiography (EC) are two imaging modalities that produce critical longitudinal data that can be analyzed for radiation-induced organ-specific injury to the lung and heart. The Medical Countermeasures Against Radiological Threats (MCART) consortium has a well-established animal model research platform that includes nonhuman primate (NHP) models of the acute radiation syndrome and the delayed effects of acute radiation exposure. These models call for a definition of the latency, incidence, severity, duration, and resolution of different organ-specific radiation-induced subsyndromes. The pulmonary subsyndromes and cardiac effects are a pair of inter-dependent syndromes impacted by exposure to potentially lethal doses of radiation. Establishing a connection between these will reveal important information about their interaction and progression of injury and recovery. Herein, we demonstrate the use of CT and EC data in the rhesus macaque models to define delayed organ injury thereby establishing: a) consistent and reliable methodology to assess radiation-induced damage to the lung and heart, b) an extensive database in normal age-matched NHP for key primary and secondary endpoints, c) identified problematic variables in imaging techniques and proposed solutions to maintain data integrity and d) initiated longitudinal analysis of potentially lethal radiation-induced damage to the lung and heart. PMID:26425907

Mitigation of radiation-induced hematopoietic injury by the polyphenolic acetate 7, 8-diacetoxy-4-methylthiocoumarin in mice

PubMed Central

Venkateswaran, Kavya; Shrivastava, Anju; Agrawala, Paban K.; Prasad, Ashok; Kalra, Namita; Pandey, Parvat R.; Manda, Kailash; Raj, Hanumantharao G.; Parmar, Virinder S.; Dwarakanath, Bilikere S.

2016-01-01

Protection of the hematopoietic system from radiation damage, and/or mitigation of hematopoietic injury are the two major strategies for developing medical countermeasure agents (MCM) to combat radiation-induced lethality. In the present study, we investigated the potential of 7, 8-diacetoxy-4-methylthiocoumarin (DAMTC) to ameliorate radiation-induced hematopoietic damage and the associated mortality following total body irradiation (TBI) in C57BL/6 mice. Administration of DAMTC 24 hours post TBI alleviated TBI-induced myelo-suppression and pancytopenia, by augmenting lymphocytes and WBCs in the peripheral blood of mice, while bone marrow (BM) cellularity was restored through enhanced proliferation of the stem cells. It stimulated multi-lineage expansion and differentiation of myeloid progenitors in the BM and induced proliferation of splenic progenitors thereby, facilitating hematopoietic re-population. DAMTC reduced the radiation-induced apoptotic and mitotic death in the hematopoietic compartment. Recruitment of pro-inflammatory M1 macrophages in spleen contributed to the immune-protection linked to the mitigation of hematopoietic injury. Recovery of the hematopoietic compartment correlated well with mitigation of mortality at a lethal dose of 9 Gy, leading to 80% animal survival. Present study establishes the potential of DAMTC to mitigate radiation-induced injury to the hematopoietic system by stimulating the re-population of stem cells from multiple lineages. PMID:27849061

CARFILZOMIB INTERACTS SYNERGISTICALY WITH HISTONE DEACETYLASE INHIBITORS IN MANTLE CELL LYMPHOMA CELLS IN VITRO AND IN VIVO

PubMed Central

Dasmahapatra, Girija; Lembersky, Dmitry; Son, Minkyeong P.; Attkisson, Elisa; Dent, Paul; Fisher, Richard. I.; Friedberg, Jonathan W.; Grant, Steven

2011-01-01

Interactions between the proteasome inhibitor carfilzomib and the HDAC inhibitors vorinostat and SNDX-275 were examined in mantle cell lymphoma (MCL) cells in vitro and in vivo. Co-administration of very low, marginally toxic carfilzomib concentrations (e.g., 3–4 nM) with minimally lethal vorinostat or SNDX-275 concentrations induced sharp increases in mitochondrial injury and apoptosis in multiple MCL cell lines and primary MCL cells. Enhanced lethalitly was associated with JNK1/2 activation, increased DNA damage (induction of λH2A.X), and ERK1/2 and AKT1/2 inactivation. Co-administration of carfilzomib and HDACIs induced a marked increase in ROS generation, and G2M arrest. Significantly, the free radical scavenger TBAP blocked carfilzomib/HDACI-mediated ROS generation, λH2A.X formation, JNK1/2 activation, and lethality. Genetic (shRNA) knock down of JNK1/2 significantly attenuated carfilzomib/HDACI-induced apoptosis, but did not prevent ROS generation or DNA damage. Carfilzomib/HDACI regimens were also active against bortezomib-resistant MCL cells. Finally, carfilzomib/vorinostat co-administrationo resulted in a pronounced reduction in tumor growth compared to single agent treatment in a MCL xenograft model associated with enhanced apoptosis, λH2A.X formation, and JNK activation. Collectively, these findings suggest that carfilzomib/HDACI regimens warrants attention in MCL. PMID:21750224

UVA photoactivation of DNA containing halogenated thiopyrimidines induces cytotoxic DNA lesions

PubMed Central

Brem, Reto; Zhang, Xiaohui; Xu, Yao-Zhong; Karran, Peter

2015-01-01

Photochemotherapy, the combination of a photosensitiser and ultraviolet (UV) or visible light, is an effective treatment for skin conditions including cancer. The high mutagenicity and non-selectivity of photochemotherapy regimes warrants the development of alternative approaches. We demonstrate that the thiopyrimidine nucleosides 5-bromo-4-thiodeoxyuridine (SBrdU) and 5-iodo-4-thiodeoxyuridine (SIdU) are incorporated into the DNA of cultured human and mouse cells where they synergistically sensitise killing by low doses of UVA radiation. The DNA halothiopyrimidine/UVA combinations induce DNA interstrand crosslinks, DNA-protein crosslinks, DNA strand breaks, nucleobase damage and lesions that resemble UV-induced pyrimidine(6-4)pyrimidone photoproducts. These are potentially lethal DNA lesions and cells defective in their repair are hypersensitive to killing by SBrdU/UVA and SIdU/UVA. DNA SIdU and SBrdU generate lethal DNA photodamage by partially distinct mechanisms that reflect the different photolabilities of their C–I and C–Br bonds. Although singlet oxygen is involved in photolesion formation, DNA SBrdU and SIdU photoactivation does not detectably increase DNA 8-oxoguanine levels. The absence of significant collateral damage to normal guanine suggests that UVA activation of DNA SIdU or SBrdU might offer a strategy to target hyperproliferative skin conditions that avoids the extensive formation of a known mutagenic DNA lesion. PMID:25747491

SOD2 deficiency in hematopoietic cells in mice results in reduced red blood cell deformability and increased heme degradation

PubMed Central

Mohanty, Joy G.; Nagababu, Enika; Friedman, Jeffrey S.; Rifkind, Joseph M.

2013-01-01

Among the three types of super oxide dismutases (SODs) known, SOD2 deficiency is lethal in neonatal mice owing to cardiomyopathy caused by severe oxidative damage. SOD2 is found in red blood cell (RBC) precursors, but not in mature RBCs. To investigate the potential damage to mature RBCs resulting from SOD2 deficiency in precursor cells, we studied RBCs from mice in which fetal liver stem cells deficient in SOD2 were capable of efficiently rescuing lethally irradiated host animals. These transplanted animals lack SOD2 only in hematopoietically generated cells and live longer than SOD2 knockouts. In these mice, approximately 2.8% of their total RBCs in circulation are iron-laden reticulocytes, with numerous siderocytic granules and increased protein oxidation similar to that seen in sideroblastic anemia. We have studied the RBC deformability and oxidative stress in these animals and the control group by measuring them with a microfluidic ektacytometer and assaying fluorescent heme degradation products with a fluorimeter, respectively. In addition, the rate of hemoglobin oxidation in RBCs from these mice and the control group were measured spectrophotometrically. The results show that RBCs from these SOD2-deficient mice have reduced deformability, increased heme degradation products, and an increased rate of hemoglobin oxidation compared with control animals, indicative of increased RBC oxidative stress. PMID:23142655

TUBERCULOSIS AND LETHAL AS WELL AS SUBLETHAL WHOLE-BODY X-RAY IRRADIATION OF GUINEA PIGS (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gabler, E.

1964-02-01

Lethally total-body-x-ray-irradiated (550 r) and simultaneously Tb- infected guinea pigs died earlier (1.5 to 3.2 days) than lethally irradiated control animals. A tuberculous focus formation could not be found microscopically or macroscopically in these guinea pigs or in sublethally irradiated and simultaneously infected animals. However, in tubcrculous control animals, which were killed at this time, specific foci could be found in liver, spleen, and lungs. Using sublethal irradiation (300 r) and simultaneous Tb inoculation half of the animals died a radiation death and the rest died of tuberculosis. It was found that 86.4% of the animals die a radiation deathmore » and 13.5% because of tuberculosis when irradiated sublethally 30 days after infection. The greatest tuberculosis foci in these animais appeared in lungs, spleen, and especially in the liver ( destroyed iiver''). Tuberculous giant cells of the Langhans-type were missing in case of irradiation and simultaneous tuberculosis. They appeared again about 20 to 30 days after irradiation. The native resistance to tuberculosis was very reduced in cases of simultaneous exposure; radioinduced cell shortage and cell damage permit tuberculous focus formation only after overcoming the acute radiation syndrome in case of sublethal irradiations. (auth)« less

Mechanical Blood Trauma in Assisted Circulation: Sublethal RBC Damage Preceding Hemolysis

PubMed Central

Olia, Salim E.; Maul, Timothy M.; Antaki, James F.; Kameneva, Marina V.

2016-01-01

After many decades of improvements in mechanical circulatory assist devices (CADs), blood damage remains a serious problem during support contributing to variety of adverse events, and consequently affecting patient survival and quality of life. The mechanisms of cumulative cell damage in continuous-flow blood pumps are still not fully understood despite numerous in vitro, in vivo, and in silico studies of blood trauma. Previous investigations have almost exclusively focused on lethal blood damage, namely hemolysis, which is typically negligible during normal operation of current generation CADs. The measurement of plasma free hemoglobin (plfHb) concentration to characterize hemolysis is straightforward, however sublethal trauma is more difficult to detect and quantify since no simple direct test exists. Similarly, while multiple studies have focused on thrombosis within blood pumps and accessories, sublethal blood trauma and its sequelae have yet to be adequately documented or characterized. This review summarizes the current understanding of sublethal trauma to red blood cells (RBCs) produced by exposure of blood to flow parameters and conditions similar to those within CADs. It also suggests potential strategies to reduce and/or prevent RBC sublethal damage in a clinically-relevant context, and encourages new research into this relatively uncharted territory. PMID:27034320

Photothermal damage is correlated to the delivery rate of time-integrated temperature

NASA Astrophysics Data System (ADS)

Denton, Michael L.; Noojin, Gary D.; Gamboa, B. Giovanna; Ahmed, Elharith M.; Rockwell, Benjamin A.

2016-03-01

Photothermal damage rate processes in biological tissues are usually characterized by a kinetics approach. This stems from experimental data that show how the transformation of a specified biological property of cells or biomolecule (plating efficiency for viability, change in birefringence, tensile strength, etc.) is dependent upon both time and temperature. However, kinetic methods require determination of kinetic rate constants and knowledge of substrate or product concentrations during the reaction. To better understand photothermal damage processes we have identified temperature histories of cultured retinal cells receiving minimum lethal thermal doses for a variety of laser and culture parameters. These "threshold" temperature histories are of interest because they inherently contain information regarding the fundamental thermal dose requirements for damage in individual cells. We introduce the notion of time-integrated temperature (Tint) as an accumulated thermal dose (ATD) with units of °C s. Damaging photothermal exposure raises the rate of ATD accumulation from that of the ambient (e.g. 37 °C) to one that correlates with cell death (e.g. 52 °C). The degree of rapid increase in ATD (ΔATD) during photothermal exposure depends strongly on the laser exposure duration and the ambient temperature.

SMK-1/PPH-4.1–mediated silencing of the CHK-1 response to DNA damage in early C. elegans embryos

PubMed Central

Kim, Seung-Hwan; Holway, Antonia H.; Wolff, Suzanne; Dillin, Andrew; Michael, W. Matthew

2007-01-01

During early embryogenesis in Caenorhabditis elegans, the ATL-1–CHK-1 (ataxia telangiectasia mutated and Rad3 related–Chk1) checkpoint controls the timing of cell division in the future germ line, or P lineage, of the animal. Activation of the CHK-1 pathway by its canonical stimulus DNA damage is actively suppressed in early embryos so that P lineage cell divisions may occur on schedule. We recently found that the rad-2 mutation alleviates this checkpoint silent DNA damage response and, by doing so, causes damage-dependent delays in early embryonic cell cycle progression and subsequent lethality. In this study, we report that mutations in the smk-1 gene cause the rad-2 phenotype. SMK-1 is a regulatory subunit of the PPH-4.1 (protein phosphatase 4) protein phosphatase, and we show that SMK-1 recruits PPH-4.1 to replicating chromatin, where it silences the CHK-1 response to DNA damage. These results identify the SMK-1–PPH-4.1 complex as a critical regulator of the CHK-1 pathway in a developmentally relevant context. PMID:17908915

Effect of Rosiglitazone on Radiation Damage in Bone Marrow Hemopoiesis

NASA Astrophysics Data System (ADS)

Benkő, Klára; Pintye, Éva; Szabó, Boglárka; Géresi, Krisztina; Megyeri, Attila; Benkő, Ilona

2008-12-01

To study radiobiological effects and drugs, which can modify radiation injury, has an importance if we would like to avoid harmful effects of radiation due to emergency situations or treat patients with malignant diseases by radiotherapy. During the long treatment schedules patients may be treated by not only anticancer but many other drugs because of accompanying diseases. These drugs may also modify radiobiological effects. Rosiglitazone pre-treatment proved to be myeloprotective and accelerated recovery of 5-fluorouracil-damaged bone marrow in our previous experiments. Our new studies are designed to evaluate whether rosiglitazone has similar beneficial effects in radiation-damaged hemopoiesis. Bone marrow damage was precipitated by total body irradiation (TBI) using single increasing doses (2-10 Gy) of γ—irradiation in groups of mice. Lethality was well correlated with damage in hemopoiesis measured by cellularity of bone marrow (LD50 values were 4.8 and 5.3 gray respectively). Rosiglitazone, an insulin-sensitizing drug, had no significant effect on bone marrow cellularity. Insulin resistance associated with obesity or diabetes mellitus type 2 is intensively growing among cancer patients requiring some kind of radiotherapy. Therefore it is important to know whether drugs used for their therapy can modify radiation effects.

Necroptotic debris including damaged mitochondria elicits sepsis-like syndrome during late-phase tularemia.

PubMed

Singh, Anju; Periasamy, Sivakumar; Malik, Meenakshi; Bakshi, Chandra Shekhar; Stephen, Laurie; Ault, Jeffrey G; Mannella, Carmen A; Sellati, Timothy J

2017-01-01

Infection with Francisella tularensis ssp. tularensis ( Ft ) strain SchuS4 causes an often lethal disease known as tularemia in rodents, non-human primates, and humans. Ft subverts host cell death programs to facilitate their exponential replication within macrophages and other cell types during early respiratory infection (⩽72 h). The mechanism(s) by which cell death is triggered remains incompletely defined, as does the impact of Ft on mitochondria, the host cell's organellar 'canary in a coal mine'. Herein, we reveal that Ft infection of host cells, particularly macrophages and polymorphonuclear leukocytes, drives necroptosis via a receptor-interacting protein kinase 1/3-mediated mechanism. During necroptosis mitochondria and other organelles become damaged. Ft -induced mitochondrial damage is characterized by: (i) a decrease in membrane potential and consequent mitochondrial oncosis or swelling, (ii) increased generation of superoxide radicals, and (iii) release of intact or damaged mitochondria into the lung parenchyma. Host cell recognition of and response to released mitochondria and other damage-associated molecular patterns engenders a sepsis-like syndrome typified by production of TNF, IL-1 β , IL-6, IL-12p70, and IFN- γ during late-phase tularemia (⩾72 h), but are absent early during infection.

What Combined Measurements From Structures and Imaging Tell Us About DNA Damage Responses

PubMed Central

Brosey, Chris A.; Ahmed, Zamal; Lees-Miller, Susan P.; Tainer, John A.

2017-01-01

DNA damage outcomes depend upon the efficiency and fidelity of DNA damage responses (DDRs) for different cells and damage. As such, DDRs represent tightly regulated prototypical systems for linking nanoscale biomolecular structure and assembly to the biology of genomic regulation and cell signaling. However, the dynamic and multifunctional nature of DDR assemblies can render elusive the correlation between the structures of DDR factors and specific biological disruptions to the DDR when these structures are altered. In this chapter, we discuss concepts and strategies for combining structural, biophysical, and imaging techniques to investigate DDR recognition and regulation, and thus bridge sequence-level structural biochemistry to quantitative biological outcomes visualized in cells. We focus on representative DDR responses from PARP/PARG/AIF damage signaling in DNA single-strand break repair and nonhomologous end joining complexes in double-strand break repair. Methods with exemplary experimental results are considered with a focus on strategies for probing flexibility, conformational changes, and assembly processes that shape a predictive understanding of DDR mechanisms in a cellular context. Integration of structural and imaging measurements promises to provide foundational knowledge to rationally control and optimize DNA damage outcomes for synthetic lethality and for immune activation with resulting insights for biology and cancer interventions. PMID:28668129

Corrupting the DNA damage response: a critical role for Rad52 in tumor cell survival.

PubMed

Lieberman, Rachel; You, Ming

2017-07-15

The DNA damage response enables cells to survive, maintain genome integrity, and to safeguard the transmission of high-fidelity genetic information. Upon sensing DNA damage, cells respond by activating this multi-faceted DNA damage response leading to restoration of the cell, senescence, programmed cell death, or genomic instability if the cell survives without proper repair. However, unlike normal cells, cancer cells maintain a marked level of genomic instability. Because of this enhanced propensity to accumulate DNA damage, tumor cells rely on homologous recombination repair as a means of protection from the lethal effect of both spontaneous and therapy-induced double-strand breaks (DSBs) in DNA. Thus, modulation of DNA repair pathways have important consequences for genomic instability within tumor cell biology and viability maintenance under high genotoxic stress. Efforts are underway to manipulate specific components of the DNA damage response in order to selectively induce tumor cell death by augmenting genomic instability past a viable threshold. New evidence suggests that RAD52, a component of the homologous recombination pathway, is important for the maintenance of tumor genome integrity. This review highlights recent reports indicating that reducing homologous recombination through inhibition of RAD52 may represent an important focus for cancer therapy and the specific efforts that are already demonstrating potential.

Nondestructive inspection of a composite missile launcher

NASA Astrophysics Data System (ADS)

Ley, O.; Chung, S.; Butera, M.; Valatka, T.; Triplett, M. H.; Godinez, V.

2012-05-01

Lighter weight alternatives are being sought to replace metallic components currently used in high performance aviation and missile systems. Benefits of lightweight, high strength carbon fiber reinforced composites in missile launchers and rocket motor cases include improved fuel economy, increased flight times, enhanced lethality and/or increased velocity. In this work, various nondestructive inspection techniques are investigated for the damage assessment of a composite missile launcher system for use in U.S. Army attack helicopters. The launcher system, which includes rails and a hardback, can be subject to impact damage from accidental tool drops, routine operation, and/or ballistic threats. The composite hardback and the launch rails both have complex geometries that can challenge the inspection process. Scanning techniques such as line scanning thermography, ultrasonic, and acousto-ultrasonics will be used and compared to determine damage detection accuracy, reliability, and efficiency. Results will also be compared with visual observations to determine if there is a correlation. The goal is to establish an inspection method that quickly and accurately assesses damage extent in order to minimize service time and return the missile system back into the field [1].

RAD9-dependent G1 arrest defines a second checkpoint for damaged DNA in the cell cycle of Saccharomyces cerevisiae.

PubMed

Siede, W; Friedberg, A S; Friedberg, E C

1993-09-01

Exposure of the yeast Saccharomyces cerevisiae to ultraviolet (UV) light, the UV-mimetic chemical 4-nitroquinoline-1-oxide (4NQO), or gamma radiation after release from G1 arrest induced by alpha factor results in delayed resumption of the cell cycle. As is the case with G2 arrest following ionizing radiation damage [Weinert, T. A. & Hartwell, L. H. (1988) Science 241, 317-322], the normal execution of DNA damage-induced G1 arrest depends on a functional yeast RAD9 gene. We suggest that the RAD9 gene product may interact with cellular components common to the G1/S and G2/M transition points in the cell cycle of this yeast. These observations define a checkpoint in the eukaryotic cell cycle that may facilitate the repair of lesions that are otherwise processed to lethal and/or mutagenic damage during DNA replication. This checkpoint apparently operates after the mating pheromone-induced G1 arrest point but prior to replicative DNA synthesis, S phase-associated maximal induction of histone H2A mRNA, and bud emergence.

Kinetically controlled fabrication of single-crystalline TiO 2 nanobrush architectures with high energy {001} facets

DOE PAGES

Fan, Lisha; Gao, Xiang; Lee, Dongkyu; ...

2017-03-01

Here, this study demonstrates that precise control of nonequilibrium growth conditions during pulsed laser deposition (PLD) can be exploited to produce single-crystalline anatase TiO 2 nanobrush architectures with large surface areas terminated with high energy {001} facets. The data indicate that the key to nanobrush formation is controlling the atomic surface transport processes to balance defect aggregation and surface-smoothing processes. High-resolution scanning transmission electron microscopy data reveal that defect-mediated aggregation is the key to TiO 2 nanobrush formation. The large concentration of defects present at the intersection of domain boundaries promotes aggregation of PLD growth species, resulting in the growthmore » of the single-crystalline nanobrush architecture. This study proposes a model for the relationship between defect creation and growth mode in nonequilibrium environments, which enables application of this growth method to novel nanostructure design in a broad range of materials.« less

Inorganic Thin-film Sensor Membranes with PLD-prepared Chalcogenide Glasses: Challenges and Implementation

PubMed Central

Kloock, Joachim P.; Mourzina, Youlia G.; Ermolenko, Yuri; Doll, Theodor; Schubert, Jürgen; Schöning, Michael J.

2004-01-01

Chalcogenide glasses offer an excellent “challenge” for their use and implementation in sensor arrays due to their good sensor-specific advantages in comparison to their crystalline counterparts. This paper will give an introduction on the preparation of chalcogenide glasses in the thin-film state. First, single microsensors have been prepared with the methods of semiconductor technology. In a next step, three microsensors are implemented onto one single silicon substrate to an “one chip” sensor array. Different ionselective chalcogenide glass membranes (PbSAgIAs2S3, CdSAgIAs2S3, CuAgAsSeTe and TlAgAsIS) were prepared by means of the pulsed laser deposition (PLD) process. The different sensor membranes and structures have been physically characterized by means of Rutherford backscattering spectrometry, scanning electron microscopy and video microscopy. The electrochemical behavior has been investigated by potentiometric measurements.

Field emission properties of different forms of carbon

NASA Astrophysics Data System (ADS)

Merkulov, Vladimir I.; Lowndes, Douglas H.; Baylor, Larry R.; Kang, Sukill

2001-06-01

The results of field emission (FE) studies are reported for three different forms of carbon: smooth amorphous carbon (a-C) films with both low and high sp 3 content prepared by pulsed-laser deposition (PLD), nanostructured carbon prepared by hot-filament chemical-vapor deposition (HFCVD), and vertically aligned carbon nanofibers (VACNFs). The studies reveal that smooth PLD carbon films are poor field emitters regardless of their sp 3 content. Conditioning of the films, which resulted in films' modification, was required to draw FE current and the emission turn-on fields were relatively high. In contrast, HFCVD carbon films exhibit very good FE properties, including low-emission turn-on fields, relatively high emission site density, and excellent durability. Finally, VACNFs also were found to possess quite promising FE properties that compete with those of HFCVD films. We believe that the latter two forms of carbon are among the most promising candidates for use as cold cathodes in commercial devices.

Growth structure and superconductivity of Bi1.7Bi0.3Sr2Ca2Cu3O10+δ ceramics synthesized from glass-crystal precursors processed in solar type ovens

NASA Astrophysics Data System (ADS)

Acrivos, J. V.; Gulamova, D. D.; Chigvinadze, J. G.; Loy, D.

2010-03-01

The growth structure as well as the superconductivity of Bi/Pb2223 alloys is reported. Periodic lattice distortions (PLD) along the ab plane diagonal, direction of superconducting transport at the transition temperature, Tc=107K are found to dominate the growth. Trransport induced by the PLD may be responsible for the sharp Tc transitions, and the bursts of frequency and Abrikosov oscillations observed above the transition temperature up to 150K. Chemical synthesis in a heliostat oven was followed by fast quenching of the melt and annealing at 840-850K, XRD near the Cu K-edge, and Tc measured by axial-torsional vibrations in transverse magnetic fields. Tc and phaase purity obtained by green solid state chemistry, in a solar spectrum, will be discussed.

Spatially resolved variations in reflectivity across iron oxide thin films

NASA Astrophysics Data System (ADS)

Kelley, Chris S.; Thompson, Sarah M.; Gilks, Daniel; Sizeland, James; Lari, Leonardo; Lazarov, Vlado K.; Matsuzaki, Kosuke; LeFrançois, Stéphane; Cinque, Gianfelice; Dumas, Paul

2017-11-01

The spin polarising properties of the iron oxide magnetite (Fe3O4) make it attractive for use in spintronic devices, but its sensitivity to compositional and structural variations make it challenging to prepare reliably. Infrared microspectroscopy and modelling are used to determine the spatial variation in the chemical composition of three thin films of iron oxide; one prepared by pulsed laser deposition (PLD), one by molecular beam epitaxy (MBE) deposition of iron whilst simultaneously flowing oxygen into the chamber and one by flowing oxygen only once deposition is complete. The technique is easily able to distinguish between films which contain metallic iron and different iron oxide phases as well as spatial variations in composition across the films. The film grown by post-oxidising iron is spatially uniform but not fully oxidised, the film grown by simultaneously oxidising iron showed spatial variation in oxide composition while the film grown by PLD was spatially uniform magnetite.

Nanostructural characterization of amorphous diamondlike carbon films

DOE Office of Scientific and Technical Information (OSTI.GOV)

SIEGAL,MICHAEL P.; TALLANT,DAVID R.; MARTINEZ-MIRANDA,L.J.

2000-01-27

Nanostructural characterization of amorphous diamondlike carbon (a-C) films grown on silicon using pulsed-laser deposition (PLD) is correlated to both growth energetic and film thickness. Raman spectroscopy and x-ray reflectivity probe both the topological nature of 3- and 4-fold coordinated carbon atom bonding and the topographical clustering of their distributions within a given film. In general, increasing the energetic of PLD growth results in films becoming more ``diamondlike'', i.e. increasing mass density and decreasing optical absorbance. However, these same properties decrease appreciably with thickness. The topology of carbon atom bonding is different for material near the substrate interface compared to materialmore » within the bulk portion of an a-C film. A simple model balancing the energy of residual stress and the free energies of resulting carbon topologies is proposed to provide an explanation of the evolution of topographical bonding clusters in a growing a-C film.« less

Pulsed laser deposition for the synthesis of monolayer WSe2

NASA Astrophysics Data System (ADS)

Mohammed, A.; Nakamura, H.; Wochner, P.; Ibrahimkutty, S.; Schulz, A.; Müller, K.; Starke, U.; Stuhlhofer, B.; Cristiani, G.; Logvenov, G.; Takagi, H.

2017-08-01

Atomically thin films of WSe2 from one monolayer up to 8 layers were deposited on an Al2O3 r-cut ( 1 1 ¯ 02 ) substrate using a hybrid-Pulsed Laser Deposition (PLD) system where a laser ablation of pure W is combined with a flux of Se. Specular X-ray reflectivities of films were analysed and were consistent with the expected thickness. Raman measurement and atomic force microscopy confirmed the formation of a WSe2 monolayer and its spatial homogeneity over the substrate. Grazing-incidence X-ray diffraction uncovered an in-plane texture in which WSe2 [ 10 1 ¯ 0 ] preferentially aligned with Al2O3 [ 11 2 ¯ 0 ]. These results present a potential to create 2D transition metal dichalcogenides by PLD, where the growth kinetics can be steered in contrast to common growth techniques like chemical vapor deposition and molecular beam epitaxy.

New insights into the autotaxin/LPA axis in cancer development and metastasis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leblanc, Raphaël; Peyruchaud, Olivier, E-mail: olivier.peyruchaud@inserm.fr

Lysophosphatidic acid (LPA) is a simple lipid with a single fatty acyl chain linked to a glycerophosphate backbone. Despite the simplicity of its structure but owing to its interactions with a series of at least six G protein-coupled receptors (LPA{sub 1–6}), LPA exerts pleiotropic bioactivities including stimulation of proliferation, migration and survival of many cell types. Autotaxin (ATX) is a unique enzyme with a lysophospholipase D (lysoPLD) activity that is responsible for the levels of LPA in the blood circulation. Both LPA receptor family members and ATX/LysoPLD are aberrantly expressed in many human cancers. This review will present the moremore » striking as well as novel experimental evidences using cell lines, cancer mouse models and transgenic animals identifying the roles for ATX and LPA receptors in cancer progression, tumor cell invasion and metastasis.« less

Possible role of gamma ray bursts on life extinction in the universe.

PubMed

Piran, Tsvi; Jimenez, Raul

2014-12-05

As a copious source of gamma rays, a nearby galactic gamma ray burst (GRB) can be a threat to life. Using recent determinations of the rate of GRBs, their luminosity function, and properties of their host galaxies, we estimate the probability that a life-threatening (lethal) GRB would take place. Amongst the different kinds of GRBs, long ones are most dangerous. There is a very good chance (but no certainty) that at least one lethal GRB took place during the past 5 gigayears close enough to Earth as to significantly damage life. There is a 50% chance that such a lethal GRB took place during the last 500×10^{6}  years, causing one of the major mass extinction events. Assuming that a similar level of radiation would be lethal to life on other exoplanets hosting life, we explore the potential effects of GRBs to life elsewhere in the Galaxy and the Universe. We find that the probability of a lethal GRB is much larger in the inner Milky Way (95% within a radius of 4 kpc from the galactic center), making it inhospitable to life. Only at the outskirts of the Milky Way, at more than 10 kpc from the galactic center, does this probability drop below 50%. When considering the Universe as a whole, the safest environments for life (similar to the one on Earth) are the lowest density regions in the outskirts of large galaxies, and life can exist in only ≈10% of galaxies. Remarkably, a cosmological constant is essential for such systems to exist. Furthermore, because of both the higher GRB rate and galaxies being smaller, life as it exists on Earth could not take place at z>0.5. Early life forms must have been much more resilient to radiation.

Both epsilon-toxin and beta-toxin are important for the lethal properties of Clostridium perfringens type B isolates in the mouse intravenous injection model.

PubMed

Fernandez-Miyakawa, Mariano E; Fisher, Derek J; Poon, Rachael; Sayeed, Sameera; Adams, Vicki; Rood, Julian I; McClane, Bruce A; Uzal, Francisco A

2007-03-01

Clostridium perfringens is capable of producing up to 15 toxins, including alpha-toxin (CPA), beta-toxin (CPB), epsilon-toxin (ETX), enterotoxin, beta2-toxin (CPB2), and perfringolysin O. Type B isolates, which must produce CPA, CPB, and ETX, are associated with animal illnesses characterized by sudden death or acute neurological signs, with or without intestinal damage. Type B pathogenesis in ruminants is poorly understood, with some animals showing lesions and clinical signs similar to those caused by either type C or type D infections. It is unknown whether host or environmental conditions are dominant for determining the outcome of type B disease or if disease outcomes are determined by variable characteristics of type B isolates. To help clarify this issue, 19 type B isolates were evaluated for toxin production during late-log-phase growth via quantitative Western blotting and by biological activity assays. Most type B isolates produced CPB levels similar to those produced by type C isolates in vitro and have the potential to produce genotype C-like disease. The lethality of type B isolate supernatants administered intravenously to mice was evaluated with or without prior trypsin treatment, and monoclonal antibody neutralization studies also were performed. Correlation analyses comparing toxin levels in type B supernatants versus lethality and neutralization studies both found that the main contributor to lethality without pretreatment with trypsin was CPB, whereas neutralization studies indicated that CPB and ETX were both important after trypsin pretreatment. At least part of the CPB produced by type B isolates remained active after trypsin treatment. However, the overall lethalities of most supernatants were lower after trypsin pretreatment. Also, there was a significant association between ETX, CPB2, and CPA production in vitro among type B isolates. However, our results suggest that both CPB and ETX are likely the most important contributors to the pathogenesis of C. perfringens type B infections in domestic animals.

Evaluation of various glyphosate concentrations on DNA damage in human Raji cells and its impact on cytotoxicity.

PubMed

Townsend, Michelle; Peck, Connor; Meng, Wei; Heaton, Matthew; Robison, Richard; O'Neill, Kim

2017-04-01

Glyphosate is a highly used active compound in agriculturally based pesticides. The literature regarding the toxicity of glyphosate to human cells has been highly inconsistent. We studied the resulting DNA damage and cytotoxicity of various glyphosate concentrations on human cells to evaluate DNA damaging potential. Utilizing human Raji cells, DNA damage was quantified using the comet assay, while cytotoxicity was further analyzed using MTT viability assays. Several glyphosate concentrations were assessed, ranging from 15 mM to 0.1 μM. We found that glyphosate treatment is lethal to Raji cells at concentrations above 10 mM, yet has no cytotoxic effects at concentrations at or below 100 μM. Treatment concentrations of 1 mM and 5 mM induce statistically significant DNA damage to Raji cells following 30-60 min of treatment, however, cells show a slow recovery from initial damage and cell viability is unaffected after 2 h. At these same concentrations, cells treated with additional compound did not recover and maintained high levels of DNA damage. While the cytotoxicity of glyphosate appears to be minimal for physiologically relevant concentrations, the compound has a definitive cytotoxic nature in human cells at high concentrations. Our data also suggests a mammalian metabolic pathway for the degradation of glyphosate may be present. Copyright © 2017 Elsevier Inc. All rights reserved.

Light, shadows and surface characteristics: the multispectral Portable Light Dome

NASA Astrophysics Data System (ADS)

Watteeuw, Lieve; Hameeuw, Hendrik; Vandermeulen, Bruno; Van der Perre, Athena; Boschloos, Vanessa; Delvaux, Luc; Proesmans, Marc; Van Bos, Marina; Van Gool, Luc

2016-11-01

A multispectral, multidirectional, portable and dome-shaped acquisition system is developed within the framework of the research projects RICH (KU Leuven) and EES (RMAH, Brussels) in collaboration with the ESAT-VISICS research group (KU Leuven). The multispectral Portable Light Dome (MS PLD) consists of a hemispherical structure, an overhead camera and LEDs emitting in five parts of the electromagnetic spectrum regularly covering the dome's inside surface. With the associated software solution, virtual relighting and enhancements can be applied in a real-time, interactive manner. The system extracts genuine 3D and shading information based on a photometric stereo algorithm. This innovative approach allows for instantaneous alternations between the computations in the infrared, red, green, blue and ultraviolet spectra. The MS PLD system has been tested for research ranging from medieval manuscript illuminations to ancient Egyptian artefacts. Preliminary results have shown that it documents and measures the 3D surface structure of objects, re-visualises underdrawings, faded pigments and inscriptions, and examines the MS results in combination with the actual relief characteristics of the physical object. Newly developed features are reflection maps and histograms, analytic visualisations of the reflection properties of all separate LEDs or selected areas. In its capacity as imaging technology, the system acts as a tool for the analysis of surface materials (e.g. identification of blue pigments, gold and metallic surfaces). Besides offering support in answering questions of attribution and monitoring changes and decay of materials, the PLD also contributes to the identification of materials, all essential factors when making decisions in the conservation protocol.

Effects of endothelin on phospholipases and generation of second messengers in cat iris sphincter and SV-CISM-2 cells.

PubMed

Abdel-Latif, A A; Ding, K H; Akhtar, R A; Yousufzai, S Y

1996-09-01

In both immortalized cat iris sphincter smooth muscle cells (SV-CISM-2 cells) and cat iris sphincter, endothelin-1 (ET-1) markedly increased the activities of phospholipase A2 (PLA2), as measured by the release of arachidonic acid (AA), phospholipase C (PLC), as measured by the production of inositol trisphosphate (IP3), and phospholipase D (PLD), as measured by the formation of phosphatidylethanol (PEt). In SV-CISM-2 cells, ET-1 induced AA release, IP3 production and PEt formation in a dose- and time-dependent manner. The dose-response studies showed that the peptide is more potent in activating PLD (EC50 = 1.2 nM) than in activating PLC (EC50 = 1.5 nM) or PLA2 (EC50 = 1.7 nM). The time course studies revealed that ET-1 activated the phospholipases in a temporal sequence in which PLA2 was stimulated first (t1/2 = 12 s), followed by PLC (t1/2 = 48 s) and lastly PLD (t1/2 = 106 s). In SV-CISM-2 cells, in contrast to the intact iris sphincter, sarafotoxin-c, an ETB receptor agonist, had no effect on the phospholipases, and indomethacin, a cyclooxygenase inhibitor, had no effect on the stimulatory effect of ET-1 on the phospholipases. These results suggest that in this smooth muscle cell line, ET-1 interacts with the ETA receptor subtype to activate, via G proteins, phospholipases A2, C and D in a temporal sequence.

Preclinical evaluation of convection-enhanced delivery of liposomal doxorubicin to treat pediatric diffuse intrinsic pontine glioma and thalamic high-grade glioma.

PubMed

Sewing, A Charlotte P; Lagerweij, Tonny; van Vuurden, Dannis G; Meel, Michaël H; Veringa, Susanna J E; Carcaboso, Angel M; Gaillard, Pieter J; Peter Vandertop, W; Wesseling, Pieter; Noske, David; Kaspers, Gertjan J L; Hulleman, Esther

2017-05-01

OBJECTIVE Pediatric high-grade gliomas (pHGGs) including diffuse intrinsic pontine gliomas (DIPGs) are primary brain tumors with high mortality and morbidity. Because of their poor brain penetrance, systemic chemotherapy regimens have failed to deliver satisfactory results; however, convection-enhanced delivery (CED) may be an alternative mode of drug delivery. Anthracyclines are potent chemotherapeutics that have been successfully delivered via CED in preclinical supratentorial glioma models. This study aims to assess the potency of anthracyclines against DIPG and pHGG cell lines in vitro and to evaluate the efficacy of CED with anthracyclines in orthotopic pontine and thalamic tumor models. METHODS The sensitivity of primary pHGG cell lines to a range of anthracyclines was tested in vitro. Preclinical CED of free doxorubicin and pegylated liposomal doxorubicin (PLD) to the brainstem and thalamus of naïve nude mice was performed. The maximum tolerated dose (MTD) was determined based on the observation of clinical symptoms, and brains were analyzed after H & E staining. Efficacy of the MTD was tested in adult glioma E98-FM-DIPG and E98-FM-thalamus models and in the HSJD-DIPG-007-Fluc primary DIPG model. RESULTS Both pHGG and DIPG cells were sensitive to anthracyclines in vitro. Doxorubicin was selected for further preclinical evaluation. Convection-enhanced delivery of the MTD of free doxorubicin and PLD in the pons was 0.02 mg/ml, and the dose tolerated in the thalamus was 10 times higher (0.2 mg/ml). Free doxorubicin or PLD via CED was ineffective against E98-FM-DIPG or HSJD-DIPG-007-Fluc in the brainstem; however, when applied in the thalamus, 0.2 mg/ml of PLD slowed down tumor growth and increased survival in a subset of animals with small tumors. CONCLUSIONS Local delivery of doxorubicin to the brainstem causes severe toxicity, even at doxorubicin concentrations that are safe in the thalamus. As a consequence, the authors could not establish a therapeutic window for treating orthotopic brainstem tumors in mice. For tumors in the thalamus, therapeutic concentrations to slow down tumor growth could be reached. These data suggest that anatomical location determines the severity of toxicity after local delivery of therapeutic agents and that caution should be used when translating data from supratentorial CED studies to treat infratentorial tumors.

Organ-Specific Blood Signatures for Host Response to Infections

DTIC Science & Technology

2012-04-03

coding regulatory RNAs with a length of 19-23 nucleotides. In a separate project studying drug- induced liver injury , we determined that...circulating miRNA (such as the liver specific miR-122) is a useful marker of liver damage. We thus conducted extensive miRNA 3 profiling studies in the...many chemokines and immune-cell specific markers (including CCL20, CXCL10, CCL2, CCL4 , CCL17, TNF, CD14, IL1RN) are induced by non-lethal infections

[Spontaneous and induced sterility by ethyl methanesulfonate (EMS) in Nigella damascena L].

PubMed

Gilot-Delhalle, J

1976-01-01

EMS-induced sterility could be very partially due to chromosomal aberrations appearing during male and female meiosis or even to mechanical abnormalities of the double fertilization. The sterility could be also related to diplontic origin (lethal factors or small deficiencies appearing in homozygous state on account of self-pollinization). Owing to our histological and genetical data, a female gametophytic origin could be mainly ascribed to EMS induced sterility. It could arise from a damage of the feeding function of the nucellus.

Littoral Combat Ship: Knowledge of Survivability and Lethality Capabilities Needed Prior to Making Major Funding Decisions

DTIC Science & Technology

2015-12-01

USS Port Royal hit a coral reef in order to provide an independent review of the damage the ship sustained. Our classified report discussed...explosion. Underwater explosions create a shock wave and a highly compressed gas bubble that expands and contracts. This can cause a type of vertical or...conditions also remains unknown. Due to the dynamic nature of waves , the Navy cannot rely on modeling and simulation alone to provide an accurate

Pharmacological Protection of the Retina against Damaging Laser Exposures: A Feasibility Study

DTIC Science & Technology

1988-09-01

subsequently administered through this route. Because rabbits can easily be lethally overdosed with barbiturates, surgical plane anesthesia was achieved by...adequately anesthetized. After removal of the second eye, the rabbit was euthanatized by barbiturate overdose . The eye was excised from the rabbit as quickly...Component mq/L uM L-glutamine 73 500 taurine 0.75 6 choline Cl 0.6 4.3 myo-inositol 27 150 Na pyruvate 22 200 ascorbate 18 100 glucose 1800 10,000

Proceedings of the NATO Radiological Human Response Subject Matter Expert Review Meeting, 26 June 2008, Albuquerque, New Mexico, United States of America

DTIC Science & Technology

2009-08-01

the proposed general casualty estimation process. The next two briefings described the technical details of the development and content of the...Forces Radiobiological Research Institute (AFRRI) Dr. Gene McClellan, Applied Research Associates (ARA) COL John Mercier, AFRRI Dr. Kyle Millage...marrow damage occurs; lethality ranges from LD50/60 to LD99/60; death occurs within 3.5 to 6 weeks with the radiation injury alone but is accelerated

Morality of Weapons of Mass Destruction: A Case Study of the Atomic Bombings of Hiroshima and Nagasaki

DTIC Science & Technology

2010-04-01

effects from biological weapons may not be apparent until after a battle . However, these weapons can do great damage to civilians, even if...justify. Ultimately, even though some chemical and biological weapons are non-lethal, Francis Harbour warns against callously using these agents due to...In this case, the United States had justly entered World War II after the Japanese attack on Pearl Harbor, meeting the criteria of just cause and

Monitoring genetic damage to ecosystems from hazardous waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, S.L.

1992-03-01

Applications of ecological toxicity testing to hazardous waste management have increased dramatically over the last few years, resulting in a greater awareness of the need for improved biomonitoring techniques. Our laboratory is developing advanced techniques to assess the genotoxic effects of environmental contamination on ecosystems. We have developed a novel mutagenesis assay using the nematode Caenorhabditis elegans, which is potentially applicable for multimedia studies in soil, sediment, and water. In addition, we are conducting validation studies of a previously developed anaphase aberration test that utilizes sea urchin embryos. Other related efforts include field validation studies of the new tests, evaluationmore » of their potential ecological relevance, and analysis of their sensitivity relative to that of existing toxicity tests that assess only lethal effects, rather than genetic damage.« less

Biophysical and biological factors determining the ability to achieve long-term cryobiological preservation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mazur, P.

1997-12-01

The BESTCapsule will maintain appropriate biological specimens for decades or centuries at cryogenic temperatures in the living state. Maintenance at temperatures below {approximately} {minus}140 C is not a problem. No ordinary chemical reactions in aqueous solutions can occur. The only source of damage will be the slow accumulation of physical damage to DNA from background ionizing radiation. But this source of damage should not become serious in less than a millennium. Rather, the main problem in cryopreservation is to devise procedures for cooling the biological specimens to {minus}196 C and returning them to normal temperatures without inflicting lethal injury. Regardlessmore » of the cell type, there are certain encompassing biophysical factors and constraints that determine whether they will survive or die during freezing and thawing. Superimposed on these may be special biological factors that apply to specific cell types. This paper will emphasize the former and give illustrative examples of the latter.« less

Lysophosphatidylethanolamine effects upon volatiles and quality of fresh-cut cantaloupe melon.

USDA-ARS?s Scientific Manuscript database

Wounding increases the hydrolysis of phospholipids mediated by phospholipase D (PLD) in plant tissues. Subsequent reactions may originate flavor-related aldehydes and alcohols. Lysophosphatidylethanolamine (LPE) is a naturally occurring phospholipid capable of inhibiting phospholipase D in vitro. Th...

Acute lethal toxicity, hyperkalemia associated with renal injury and hepatic damage after intravenous administration of cadmium nitrate in rats.

PubMed

Dote, Emi; Dote, Tomotaro; Shimizu, Hiroyasu; Shimbo, Yukari; Fujihara, Michiko; Kono, Koichi

2007-01-01

Cadmium nitrate Cd(NO(3))(2) (CdN) is commonly used in Ni-Cd battery factories. The possibility of accidental exposure to CdN is great. CdN is very soluble in water compared to other Cd compounds. Therefore, acute toxicity would be expected to be quick due to rapid absorption after exposure. However, the mechanisms of CdN toxicity have not been fully elucidated. We investigated the acute lethal toxicity and harmful systemic effects of acute exposure to large doses of CdN. The lethal dose and dose-response study of the liver and kidney were determined after intravenous administration of CdN in rats. The LD(50) of CdN was determined to be 5.5 mg/kg. Doses of 2.1, 4.2, 6.3 mg/kg were selected for the dose-response study. Liver injury was induced at doses greater than 4.2 mg/kg. Severe hepatic injury occurred in the 6.3 mg/kg group, which would have been caused by acute exposure to the high concentration of Cd that exceeded the critical concentration in hepatic tissue. A remarkable decrease in urine volume in the 6.3 mg/kg group indicated acute renal failure. A decrease in creatinine clearance suggested acute glomerular dysfunction at doses greater than 4.2 mg/kg. Increases in urinary N-acetyl-beta-D-glucosaminidase/creatinine, beta(2)-microglobulin and glucose in the 6.3 mg/kg group indicated proximal tubular injury. Secretion of K ion was also severely affected by proximal tubular injury and severe decreases in urine volume, and an increase in serum K ion was identified at doses greater than 4.2 mg/kg. Thus severe hyperkalemia might be associated with the cardiac-derived lethal toxicity of CdN.

Candidate synthetic lethality partners to PARP inhibitors in the treatment of ovarian clear cell cancer

PubMed Central

Kawahara, Naoki; Ogawa, Kenji; Nagayasu, Mika; Kimura, Mai; Sasaki, Yoshikazu; Kobayashi, Hiroshi

2017-01-01

Inhibitors of poly(ADP-ribose) polymerase (PARP) are new types of personalized treatment of relapsed platinum-sensitive ovarian cancer harboring BRCA1/2 mutations. Ovarian clear cell cancer (CCC), a subset of ovarian cancer, often appears as low-stage disease with a higher incidence among Japanese. Advanced CCC is highly aggressive with poor patient outcome. The aim of the present study was to determine the potential synthetic lethality gene pairs for PARP inhibitions in patients with CCC through virtual and biological screenings as well as clinical studies. We conducted a literature review for putative PARP sensitivity genes that are associated with the CCC pathophysiology. Previous studies identified a variety of putative target genes from several pathways associated with DNA damage repair, chromatin remodeling complex, PI3K-AKT-mTOR signaling, Notch signaling, cell cycle checkpoint signaling, BRCA-associated complex and Fanconi's anemia susceptibility genes that could be used as biomarkers or therapeutic targets for PARP inhibition. BRCA1/2, ATM, ATR, BARD1, CCNE1, CHEK1, CKS1B, DNMT1, ERBB2, FGFR2, MRE11A, MYC, NOTCH1 and PTEN were considered as candidate genes for synthetic lethality gene partners for PARP interactions. When considering the biological background underlying PARP inhibition, we hypothesized that PARP inhibitors would be a novel synthetic lethal therapeutic approach for CCC tumors harboring homologous recombination deficiency and activating oncogene mutations. The results showed that the majority of CCC tumors appear to have indicators of DNA repair dysfunction similar to those in BRCA-mutation carriers, suggesting the possible utility of PARP inhibitors in a subset of CCC. PMID:29109859

The case for intrauterine stem cell transplantation.

PubMed

Mattar, Citra N; Biswas, Arijit; Choolani, Mahesh; Chan, Jerry K Y

2012-10-01

The clinical burden imposed by the collective group of monogenic disorders demands novel therapies that are effective at achieving phenotypic cure early in the disease process before the development of permanent organ damage. This is important for lethal diseases and also for non-perinatally lethal conditions that are characterised by severe disability with little prospect of postnatal cure. Where postnatal treatments are limited to palliative options, intrauterine stem-cell therapies may offer the potential to arrest pathogenesis in the early undamaged fetus. Intrauterine stem-cell transplantation has been attempted for a variety of diseases, but has only been successful in immune deficiency states in the presence of a competitive advantage for donor cells. This disappointing clinical record requires preclinical investigations into strategies that improve donor cell engraftment, including optimising the donor cell source and manipulating the microenvironment to facilitate homing. This chapter aims to outline the current challenges of intrauterine stem-cell therapy. Copyright © 2012 Elsevier Ltd. All rights reserved.

Histone deacetylase inhibitors promote the tumoricidal effect of HAMLET.

PubMed

Brest, Patrick; Gustafsson, Mattias; Mossberg, Ann-Kristin; Gustafsson, Lotta; Duringer, Caroline; Hamiche, Ali; Svanborg, Catharina

2007-12-01

Histone deacetylase inhibitors (HDIs) and HAMLET (human alpha-lactalbumin made lethal to tumor cells) interact with histones, modify the structure of chromatin, and trigger tumor cell death. This study investigated how the combination of HDIs and HAMLET influences cell viability, histone acetylation, and DNA integrity. The pretreatment of tumor cells with HDIs was shown to enhance the lethal effect of HAMLET and the histone hyperacetylation response to HDIs increased even further after HAMLET treatment. HDIs and HAMLET were shown to target different histone domains as HAMLET bound tailless core histones, whereas HDIs modify the acetylation of the histone tail. DNA damage in response to HAMLET was increased by HDIs. The DNA repair response (p21WAFI expression) was induced by both agonists but abolished when the two agonists were combined. The results suggest that the synergy of HDIs and HAMLET is based on different but converging death pathways, both involving chromatin alterations. We speculate that HAMLET and HDIs might be combined to promote tumor cell death in vivo.

Small-Molecule Inhibitors Targeting DNA Repair and DNA Repair Deficiency in Research and Cancer Therapy.

PubMed

Hengel, Sarah R; Spies, M Ashley; Spies, Maria

2017-09-21

To maintain stable genomes and to avoid cancer and aging, cells need to repair a multitude of deleterious DNA lesions, which arise constantly in every cell. Processes that support genome integrity in normal cells, however, allow cancer cells to develop resistance to radiation and DNA-damaging chemotherapeutics. Chemical inhibition of the key DNA repair proteins and pharmacologically induced synthetic lethality have become instrumental in both dissecting the complex DNA repair networks and as promising anticancer agents. The difficulty in capitalizing on synthetically lethal interactions in cancer cells is that many potential targets do not possess well-defined small-molecule binding determinates. In this review, we discuss several successful campaigns to identify and leverage small-molecule inhibitors of the DNA repair proteins, from PARP1, a paradigm case for clinically successful small-molecule inhibitors, to coveted new targets, such as RAD51 recombinase, RAD52 DNA repair protein, MRE11 nuclease, and WRN DNA helicase. Copyright © 2017 Elsevier Ltd. All rights reserved.

Theoretical models and simulation codes to investigate bystander effects and cellular communication at low doses

NASA Astrophysics Data System (ADS)

Ballarini, F.; Alloni, D.; Facoetti, A.; Mairani, A.; Nano, R.; Ottolenghi, A.

Astronauts in space are continuously exposed to low doses of ionizing radiation from Galactic Cosmic Rays During the last ten years the effects of low radiation doses have been widely re-discussed following a large number of observations on the so-called non targeted effects in particular bystander effects The latter consist of induction of cytogenetic damage in cells not directly traversed by radiation most likely as a response to molecular messengers released by directly irradiated cells Bystander effects which are observed both for lethal endpoints e g clonogenic inactivation and apoptosis and for non-lethal ones e g mutations and neoplastic transformation tend to show non-linear dose responses This might have significant consequences in terms of low-dose risk which is generally calculated on the basis of the Linear No Threshold hypothesis Although the mechanisms underlying bystander effects are still largely unknown it is now clear that two types of cellular communication i e via gap junctions and or release of molecular messengers into the extracellular environment play a fundamental role Theoretical models and simulation codes can be of help in elucidating such mechanisms In the present paper we will review different available modelling approaches including one that is being developed at the University of Pavia The focus will be on the different assumptions adopted by the various authors and on the implications of such assumptions in terms of non-targeted radiobiological damage and more generally low-dose

The Protective Effect of Dietary Arthrospira (Spirulina) maxima Against Mutagenicity Induced by Benzo[alpha]pyrene in Mice

PubMed Central

Garduño-Siciliano, Leticia; Martínez-Galero, Elizdath; Mojica-Villegas, Angélica; Pages, Nicole; Gutiérrez-Salmeán, Gabriela

2014-01-01

Abstract Benzo[alpha]pyrene (B[α]P) was used to test the possible antimutagenic effects of Arthrospira (Spirulina) maxima (SP) on male and female mice. SP was orally administered at 0, 200, 400, or 800 mg/kg of body weight to animals of both sexes for 2 weeks before starting the B[α]P (intraperitoneal injection) at 125 mg/kg of body weight for 5 consecutive days. For the male dominant lethal test, each male was caged with two untreated females per week for 3 weeks. For the female dominant lethal test, each female was caged for 1 week with one untreated male. All the females were evaluated 13–15 days after mating for incidence of pregnancy, total corpora lutea, total implants and pre- and postimplant losses. SP protected from B[α]P-induced pre- and postimplant losses in the male dominant lethal test, and from B[α]P-induced postimplantation losses in treated females. Moreover, SP treatment significantly reduced the detrimental effect of B[α]P on the quality of mouse semen. Our results illustrate the protective effects of SP in relation to B[α]P-induced genetic damage to germ cells. We conclude that SP, owing mainly to the presence of phycocyanin, could be of potential clinical interest in cancer treatment or prevention of relapse. PMID:24787733

A synthetic lethal screen identifies ATR-inhibition as a novel therapeutic approach for POLD1-deficient cancers

PubMed Central

Hocke, Sandra; Guo, Yang; Job, Albert; Orth, Michael; Ziesch, Andreas; Lauber, Kirsten; De Toni, Enrico N; Gress, Thomas M.; Herbst, Andreas; Göke, Burkhard; Gallmeier, Eike

2016-01-01

The phosphoinositide 3-kinase-related kinase ATR represents a central checkpoint regulator and mediator of DNA-repair. Its inhibition selectively eliminates certain subsets of cancer cells in various tumor types, but the underlying genetic determinants remain enigmatic. Here, we applied a synthetic lethal screen directed against 288 DNA-repair genes using the well-defined ATR knock-in model of DLD1 colorectal cancer cells to identify potential DNA-repair defects mediating these effects. We identified a set of DNA-repair proteins, whose knockdown selectively killed ATR-deficient cancer cells. From this set, we further investigated the profound synthetic lethal interaction between ATR and POLD1. ATR-dependent POLD1 knockdown-induced cell killing was reproducible pharmacologically in POLD1-depleted DLD1 cells and a panel of other colorectal cancer cell lines by using chemical inhibitors of ATR or its major effector kinase CHK1. Mechanistically, POLD1 depletion in ATR-deficient cells caused caspase-dependent apoptosis without preceding cell cycle arrest and increased DNA-damage along with impaired DNA-repair. Our data could have clinical implications regarding tumor genotype-based cancer therapy, as inactivating POLD1 mutations have recently been identified in small subsets of colorectal and endometrial cancers. POLD1 deficiency might thus represent a predictive marker for treatment response towards ATR- or CHK1-inhibitors that are currently tested in clinical trials. PMID:26755646

Low susceptibility of NC/Nga mice to tumor necrosis factor-alpha-mediated lethality and hepatocellular damage with D-galactosamine sensitization.

PubMed

Koide, Naoki; Morikawa, Akiko; Naiki, Yoshikazu; Tumurkhuu, Gantsetseg; Yoshida, Tomoaki; Ikeda, Hiroshi; Yokochi, Takashi

2009-02-01

The susceptibility of NC/Nga mice to tumor necrosis factor (TNF)-alpha was examined by using sensitization with d-galactosamine (d-GalN). Administration of TNF-alpha and d-GalN killed none of the NC/Nga mice, whereas it killed all of the BALB/c mice. Treatment with TNF-alpha and d-GalN caused few hepatic lesions in NC/Nga mice but massive hepatocellular apoptosis in BALB/c mice. Unlike BALB/c mice, there was no elevation in caspase 3 and 8 activities in the livers of NC/Nga mice receiving TNF-alpha and d-GalN. On the other hand, administration of anti-Fas antibody definitely killed both NC/Nga and BALB/c mice via activation of caspases 3 and 8. Treatment with TNF-alpha and d-GalN led to translocation of nuclear factor (NF)-kappaB in NC/Nga and BALB/c mice. However, NF-kappaB translocation was sustained in NC/Nga mice, although it disappeared in BALB/c mice 7 h after the treatment. NF-kappaB inhibitors activated caspases 3 and 8, and enhanced TNF-alpha-mediated lethality in NC/Nga. Taken together, the low susceptibility of NC/Nga mice to TNF-alpha-mediated lethality was suggested to be responsible for the sustained NF-kappaB activation.

Dose-response and histopathological study, with special attention to the hypophysis, of the differential effects of domoic acid on rats and mice.

PubMed

Vieira, Andrés Crespo; Martínez, J Manuel Cifuentes; Pose, Roberto Bermúdez; Queijo, Álvaro Antelo; Posadas, Nuria Alemañ; López, Luis M Botana

2015-05-01

The effects of the neurotoxin domoic acid (DA) in the central nervous system of rodents (essentially rats and mice) after intraperitoneal administration have been profusely studied in the past. These observations have shown that the toxin induces similar symptoms and pathology in both species, but the lethality varies greatly. This article addresses the common and specific histopathological effects in rats and mice and the difference in sensitivity of these species to DA. Various sublethal and lethal doses were employed in mice (from 3 mg/kg to 8 mg/kg) to observe their neurotoxicity by using different histological techniques, and these results were compared with the pathological effects after the administration of LD50 in rats (2.5 mg/kg). Additionally we also detected the presence of this toxin in various tissues by means of immunohistochemistry. Our results showed that rats are more vulnerable than mice to the neurotoxic effects of DA after intraperitoneal inoculation: lethality was extremely high in rats and the toxin produced hippocampal damage in rats surviving the intoxication, while lesions were not observed in DA-inoculated mice. As for similarities between rats and mice, both displayed similar clinical signs and in both the toxin was detected in the hypophysis by immunohistochemistry, a brain region not reported to date as target of the toxin. © 2015 Wiley Periodicals, Inc.

ATR suppresses endogenous DNA damage and allows completion of homologous recombination repair.

PubMed

Brown, Adam D; Sager, Brian W; Gorthi, Aparna; Tonapi, Sonal S; Brown, Eric J; Bishop, Alexander J R

2014-01-01

DNA replication fork stalling or collapse that arises from endogenous damage poses a serious threat to genome stability, but cells invoke an intricate signaling cascade referred to as the DNA damage response (DDR) to prevent such damage. The gene product ataxia telangiectasia and Rad3-related (ATR) responds primarily to replication stress by regulating cell cycle checkpoint control, yet it's role in DNA repair, particularly homologous recombination (HR), remains unclear. This is of particular interest since HR is one way in which replication restart can occur in the presence of a stalled or collapsed fork. Hypomorphic mutations in human ATR cause the rare autosomal-recessive disease Seckel syndrome, and complete loss of Atr in mice leads to embryonic lethality. We recently adapted the in vivo murine pink-eyed unstable (pun) assay for measuring HR frequency to be able to investigate the role of essential genes on HR using a conditional Cre/loxP system. Our system allows for the unique opportunity to test the effect of ATR loss on HR in somatic cells under physiological conditions. Using this system, we provide evidence that retinal pigment epithelium (RPE) cells lacking ATR have decreased density with abnormal morphology, a decreased frequency of HR and an increased level of chromosomal damage.

MicroRNA-203 Modulates the Radiation Sensitivity of Human Malignant Glioma Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Ji Hyun; Hwang, Yeo Hyun; Lee, David J.

Purpose: We investigated whether miR-203 could modulate the radiation sensitivity of glioblastoma (GBM) cells and which target gene(s) could be involved. Methods and Materials: Three human malignant glioma (MG) cell lines and normal human astrocytes were transfected with control microRNA, pre-miR-203, or antisense miR-203. Real-time PCR (RT-PCR), clonogenic assays, immunofluorescence, and invasion/migration assays were performed. To predict the target(s), bioinformatics analyses using microRNA target databases were performed. Results: Overexpression of miR-203 increased the radiation sensitivity of all 3 human MG cell lines and prolonged radiation-induced γ-H2AX foci formation. Bioinformatics analyses suggested that miR-203 could be involved in post-transcriptional control of DNAmore » repair, PI3K/AKT, SRC, and JAK/STAT3 and the vascular signaling pathway. Western blot analysis validated the fact that miR-203 downregulated ATM, RAD51, SRC, PLD2, PI3K-AKT, JAK-STAT3, VEGF, HIF-1α, and MMP2. Overexpression of miR-203 inhibited invasion and migration potentials, downregulated SLUG and Vimentin, and upregulated Claudin-1 and ZO1. Conclusions: These data demonstrate that miR-203 potentially controls DNA damage repair via the PI3K/AKT and JAK/STAT3 pathways and may collectively contribute to the modulation of radiation sensitivity in MG cells by inhibiting DNA damage repair, prosurvival signaling, and epithelium-mesenchyme transition. Taken together, these findings demonstrate that miR-203 could be a target for overcoming the radiation resistance of GBM.« less

Differential inhibitory effects of 2-azafluorenones on PI-PLC activation but not on PC-PLC- or PC-PLD-activation induced by histamine, PAF, PMA or A23187 in C6 glioma cells.

PubMed

Wang, Hai-Long; Wang, Li-Chuan; Wei, Jiann-Wu

2013-02-28

In this study, C6 glioma cells were used to test the effects of 2-azafluorenone and its related compounds on membrane phosphatidylinositol (PI) and phosphatidylcholine (PC) turnover. An increase of [³H]-labeled inositol phosphate (IP1) formation by histamine (100 μM) or A23187 (100 nM) via the activation of phosphatidylinositol-specific phospholipase C (PI-PLC) to breakdown labeled substrate was observed, and this effect could be partially blocked by about half at 100 μM of 2-azafluorenones. Histamine induced the increase of IP1 formation, but failed to cause an increase in extracellularly releasing of [3H]choline metabolites, or intracellular accumulation of [³H]phosphscholine. However, platelet activation factor (PAF) from 0.2 to 1 μM, and phorbol 12-myristate-13-acetate (PMA) at 1 μM caused an increase in extracellularly releasing of [³H]choline metabolites, and intracellular accumulation of [³H]phosphocholine via the activation on phosphatidylcholine (PC)-PLC. These responses of PAF and PMA were not affected by 2-azafluorenone or 4-methyl-2-azafluorenone even at high concentration (10⁻⁴ M). A23187 induced an increase of intracellular [³H]choline release via the activation of PCphospholipase D (PLD). This increasing effect of 100 nM A23187 was not affected by 2-azafluorenone or 4-methyl-2-azafluorenone even at a high concentration of 10⁻⁴ M. In summary, the inhibitory effect of 2-azafluorenone and its related compound 4-methyl-2-azafluorenone was observed selectively on PIPLC, but not on PC-PLC or PC-PLD based on changes of products after the activation of these enzymes.

Perinatal asphyxia results in altered expression of the hippocampal acylethanolamide/endocannabinoid signaling system associated to memory impairments in postweaned rats.

PubMed

Blanco, Eduardo; Galeano, Pablo; Holubiec, Mariana I; Romero, Juan I; Logica, Tamara; Rivera, Patricia; Pavón, Francisco J; Suarez, Juan; Capani, Francisco; Rodríguez de Fonseca, Fernando

2015-01-01

Perinatal asphyxia (PA) is an obstetric complication that strongly affects the CNS. The endocannabinoid system (ECS) is a lipid transmitter system involved in several physiological processes including synaptic plasticity, neurogenesis, memory, and mood. Endocannabinoids, and other acylethanolamides (AEs) without endocannabinoid activity, have recently received growing attention due to their potential neuroprotective functions in neurological disorders, including cerebral ischemia. In the present study, we aimed to analyze the changes produced by PA in the major metabolic enzymes and receptors of the ECS/AEs in the hippocampus using a rodent model of PA. To induce PA, we removed uterine horns from ready-to-deliver rats and immersed them into a water bath during 19 min. Animals delivered spontaneously or by cesarean section were employed as controls. At 1 month of age, cognitive functions were assessed and immunohistochemical procedures were carried out to determine the expression of NeuN and glial fibrillary acidic protein, enzymes responsible for synthesis (DAGLα and NAPE-PLD) and degradation (FAAH) of ECS/AEs and their receptors (CB1 and PPARα) in the hippocampus. Postweaned asphyctic rats showed impaired recognition and spatial reference memory that were accompanied by hippocampal astrogliosis and changes in the expression of enzymes and receptors. The most remarkable findings in asphyctic rats were a decrease in the expression of NAPE-PLD and PPARα in both hippocampal areas CA1 and CA3. In addition, postweaned cesarean delivery rats showed an increase in the immunolabeling for FAAH in the hippocampal CA3 area. Since, NAPE-PLD and PPARα are proteins that participate in the biochemical process of AEs, specially the neuroprotective oleoylethanolamide, these results suggest that PA dysregulates this system. These data encourage conducting future studies using AEs as potential neuroprotective compounds in animal models of PA.

Pulsed laser deposition to synthesize the bridge structure of artificial nacre: Comparison of nano- and femtosecond lasers

NASA Astrophysics Data System (ADS)

Melaibari, Ammar A.; Molian, Pal

2012-11-01

Nature offers inspiration to new adaptive technologies that allow us to build amazing shapes and structures such as nacre using synthetic materials. Consequently, we have designed a pulsed laser ablation manufacturing process involving thin film deposition and micro-machining to create hard/soft layered "brick-bridge-mortar" nacre of AlMgB14 (hard phase) with Ti (soft phase). In this paper, we report pulsed laser deposition (PLD) to mimic brick and bridge structures of natural nacre in AlMgB14. Particulate formation inherent in PLD is exploited to develop the bridge structure. Mechanical behavior analysis of the AlMgB14/Ti system revealed that the brick is to be 250 nm thick, 9 μm lateral dimensions while the bridge (particle) is to have a diameter of 500 nm for a performance equivalent to natural nacre. Both nanosecond (ns) and femtosecond (fs) pulsed lasers were employed for PLD in an iterative approach that involves varying pulse energy, pulse repetition rate, and target-to-substrate distance to achieve the desired brick and bridge characteristics. Scanning electron microscopy, x-ray photoelectron spectroscopy, and optical profilometer were used to evaluate the film thickness, particle size and density, stoichiometry, and surface roughness of thin films. Results indicated that both ns-pulsed and fs-pulsed lasers produce the desired nacre features. However, each laser may be chosen for different reasons: fs-pulsed laser is preferred for much shorter deposition time, better stoichiometry, uniform-sized particles, and uniform film thickness, while ns-pulsed laser is favored for industrial acceptance, reliability, ease of handling, and low cost.

Insulin promotes diacylglycerol kinase activation by different mechanisms in rat cerebral cortex synaptosomes.

PubMed

Zulian, Sandra E; Ilincheta de Boschero, Mónica G; Giusto, Norma M

2006-10-01

The mechanism by which insulin increases diacylglycerol kinase (DAGK) activity has been studied in cerebral cortex (CC) synaptosomes from adult (3-4 months of age) rats. The purpose of this study was to identify the role of phospholipases C and D (PLC and PLD) in DAGK activation by insulin. Neomycin, an inhibitor of PLC phosphatidylinositol-bisphosphate (PIP2) specific; ethanol, an inhibitor of phosphatidic acid (PA) formation by the promotion of a transphosphatidyl reaction of phosphatidylcholine phospholipase D (PC-PLD); and DL propranolol, an inhibitor of phosphatidate phosphohydrolase (PAP), were used in this study. Insulin (0.1 microM) shielded an increase in PA synthesis by [32P] incorporation using [gamma-32P]ATP as substrate and endogenous diacylglycerol (DAG) as co-substrate. This activated synthesis was strongly inhibited either by ethanol or DL propranolol. Pulse chase experiments also showed a PIP2-PLC activation within 1 min exposure to insulin. When exogenous unsaturated 18:0-20:4 DAG was present, insulin increased PA synthesis significantly. However, this stimulatory effect was not observed in the presence of exogenous saturated (di-16:0). In the presence of R59022, a selective DAGK inhibitor, insulin exerted no stimulatory effect on [32P]PA formation, suggesting a strong relationship between increased PA formation by insulin and DAGK activity. These data indicate that the increased synthesis of PA by insulin could be mediated by the activation of both a PC-PLD pathway to provide DAG and a direct DAGK activation that is associated to the use of 18:0-20:4 DAG species. PIP2-PLC activation may contribute at least partly to the insulin effect on DAGK activity. Copyright 2006 Wiley-Liss, Inc.

The role of phosphoinositide 3-kinase and phosphatidic acid in the regulation of mammalian target of rapamycin following eccentric contractions

PubMed Central

O’Neil, T K; Duffy, L R; Frey, J W; Hornberger, T A

2009-01-01

Resistance exercise induces a hypertrophic response in skeletal muscle and recent studies have begun to shed light on the molecular mechanisms involved in this process. For example, several studies indicate that signalling by the mammalian target of rapamycin (mTOR) is necessary for a hypertrophic response. Furthermore, resistance exercise has been proposed to activate mTOR signalling through an upstream pathway involving the phosphoinositide 3-kinase (PI3K) and protein kinase B (PKB); however, this hypothesis has not been thoroughly tested. To test this hypothesis, we first evaluated the temporal pattern of signalling through PI3K–PKB and mTOR following a bout of resistance exercise with eccentric contractions (EC). Our results indicated that the activation of signalling through PI3K–PKB is a transient event (<15 min), while the activation of mTOR is sustained for a long duration (>12 h). Furthermore, inhibition of PI3K–PKB activity did not prevent the activation of mTOR signalling by ECs, indicating that PI3K–PKB is not part of the upstream regulatory pathway. These observations led us to investigate an alternative pathway for the activation of mTOR signalling involving the synthesis of phosphatidic acid (PA) by phospholipase D (PLD). Our results demonstrate that ECs induce a sustained elevation in [PA] and inhibiting the synthesis of PA by PLD prevented the activation of mTOR. Furthermore, we determined that similar to ECs, PA activates mTOR signalling through a PI3K–PKB-independent mechanism. Combined, the results of this study indicate that the activation of mTOR following eccentric contractions occurs through a PI3K–PKB-independent mechanism that requires PLD and PA. PMID:19470781

The role of diacylglycerol kinase ζ and phosphatidic acid in the mechanical activation of mammalian target of rapamycin (mTOR) signaling and skeletal muscle hypertrophy.

PubMed

You, Jae-Sung; Lincoln, Hannah C; Kim, Chan-Ran; Frey, John W; Goodman, Craig A; Zhong, Xiao-Ping; Hornberger, Troy A

2014-01-17

The activation of mTOR signaling is essential for mechanically induced changes in skeletal muscle mass, and previous studies have suggested that mechanical stimuli activate mTOR (mammalian target of rapamycin) signaling through a phospholipase D (PLD)-dependent increase in the concentration of phosphatidic acid (PA). Consistent with this conclusion, we obtained evidence which further suggests that mechanical stimuli utilize PA as a direct upstream activator of mTOR signaling. Unexpectedly though, we found that the activation of PLD is not necessary for the mechanically induced increases in PA or mTOR signaling. Motivated by this observation, we performed experiments that were aimed at identifying the enzyme(s) that promotes the increase in PA. These experiments revealed that mechanical stimulation increases the concentration of diacylglycerol (DAG) and the activity of DAG kinases (DGKs) in membranous structures. Furthermore, using knock-out mice, we determined that the ζ isoform of DGK (DGKζ) is necessary for the mechanically induced increase in PA. We also determined that DGKζ significantly contributes to the mechanical activation of mTOR signaling, and this is likely driven by an enhanced binding of PA to mTOR. Last, we found that the overexpression of DGKζ is sufficient to induce muscle fiber hypertrophy through an mTOR-dependent mechanism, and this event requires DGKζ kinase activity (i.e. the synthesis of PA). Combined, these results indicate that DGKζ, but not PLD, plays an important role in mechanically induced increases in PA and mTOR signaling. Furthermore, this study suggests that DGKζ could be a fundamental component of the mechanism(s) through which mechanical stimuli regulate skeletal muscle mass.

Why is there evidence for flowing ice at mid-latitudes on Mars but not at the poles?

NASA Astrophysics Data System (ADS)

Smith, I. B.

2017-12-01

Ice has been detected on Mars in many places, from the polar caps, to mid-latitudes. In many locations there exists evidence for glacial flow. This raises the possibility of flow for the polar layered deposits (PLD). Since the >2000 m thick ice deposits were first observed, speculation about their flow status have persisted. Several stratigraphic predictions regarding flow have been made (Figure 1), but these predictions are not supported with observational data (Smith and Holt 2015) The disagreement between model and observations has led to a general consensus that the polar ice flows more slowly than other processes acting on the PLD, but the reasoning is not understood. Here I posit that the polar layered deposits do not act as a single, generic ice sheet. Instead, they act as a stack of thin ice sheets, where each layer is separated by a boundary of dust, and all layers flow individually. The layers act as barriers to vertical flow, so the viscosity of the cold ice can only be expressed through lateral expansion. I plan to present a simple experiment demonstrating the multi-layer, stacked flow hypothesis. I will demonstrate that the layers themselves flow but do not deform the entire ice sheet, as previously predicted. This allows for the PLD to retain their steep slopes and prevents many of the predicted flow features to form. The major component of this hypothesis is that the dust layers hinder flow. Thus, constraining the friction coefficient, viscosity, tensile strength and compressibility of the dust layers becomes an important next step for testing the stacked, multi-layer flow scenario. Acknowledgements: Thanks to Eric Larour and David Goldsby for helpful comments.